I will partially agree with you. The only point I wanna make is that Doran's shield is a fine item for seju top. And no, you are no hater for saying you can't understand a word, I guess the same happens to anyone. I mean, if you can't speak a language, what's the point in writing a guide in that language...

Of course all the haters will hate me even more now, but I love Sejuani, so let’s make a serious talk bout ur guide (oh and sorry for not makein’ it all that flashy with those icons but I was makin’ this comment in quite a hurry .. so once again sorry if I made too many mistakes).

runes:
magic pen runes vs hubrid pen runes – u trade 6 armor pen wchich would let u last hit mionions a bit easier for whole 2 magic pens which make no difference early as Sejuani won’t make much use of her W nor late when 2 damages mean nth.
quint of AP – she only seems to make use of those, but honestly these r only good for high burst AP champs while Sejuani is DPS dependamnt more than her low burst
glyphs of magic pen – that magic pen is so low not even minions will feel difference…

skill sequence:
startin’ with “w” is a realy bad idea, especially while playin’ top Sejuani cause u will not make long trades and “northern winds” base damage is very low yet it scales with her HPs nicely which can lead to insane LATE game DPS, u also leave her without her mobility normaly provided by “Arctic Assault” and that can be disastreous against aggressively playin’ counter-champs cause u have no chance to win early trades nor get to lv2 before ur opponent unless he spends too much helpin’ his jungler which will happen rarely so u might die lv1 or lv2 when doin’ this ur way .. and that’s disastrous. Also u max ur “w” as ur 1st skill which will not let u do much until u get warmogs or 2 other HP based items and u can’t zone a ranged poke opponent without ur maxed “E”s early game burst damage and insane slow and that means u’r the one getting’ zoned, missin’ not only some gold which Sejuani often does very early but also lots of exp which means u can’t even help ur bot lane effectively with ur teleport cause ur not only simply behind but u will not bring all those slows that can help ur teammates run away or land much much more damages when u tp-gank.

masteries:
knowin’ that Sejuani’s main damage source in mid and late game is “(Flail of the) Northern Winds” and how well it scales with HPs (even after that re-release insanely painfull nerf) there’s absolutely no point in pickin’ such offensive focused masteries cause u can pick defensive ones and still deal high damages in late game while also because of her damage beein’ DPS focused much more than burst focused u have to be able to survive long enough to deliver all that DPS so pickin’ offensive masteries u miss bout half her power while not getting’ more damages at all

introduction:
even though all Sejuani’s skllis scale with AP it’s only her second scalein’ priority after HPs cause both her “w” and passive scale with it (1st one givin’ damages 2nd one beein’ much more effective if there r more HPs to be protected by that armor) and beein’ a meele champion that needs defensive stats even if there rn’t any assasins also she’s not a burster at all, her early mid game burst is not half bad but her early and late game burst damage is nearly non-existant.
“Frost armor” gives u scalein’ (scales with ur aggression), not flat armor and if u go for very early trades as Sejuani u’r just suicidein’ unless u play against sm1 that has no idea but both his champion and Sejuani.
“Arctic Assault” deals damages based on TARGETS max HPs which r not always so gr8, especially in the age of the 4 assasins + semi-tank support we have to face now in mid and high tier ranked games while Northern Winds deal damages based on ur own HPs while ur build provides nearly no bonus HPs…

Cons:
Sejuani has early mana problems only if u’r constantly tryin’ too go for those early game trades which she can nearly never win so it’s more bout u constantly burnin’ ur mana mindlessly than her own costs, while also “Northern Winds” cost is realy low and ur guide says u r maxin’ this one 1st… u lso miss the fact that with inceasin’ number of champions with targets max HPs based skills there r many counter-picks for her especially for early and mid game so u have to pick her late in ranked games.

Items:
U start with a Dorans Shield which to be honest works only against AD based no flat armor pens top laners … too many requirements to make it work; compared to Crystalline Flask it’s pretty useless as this one gives u free pots for early and mid game HP regeneration and MP regeneration and u r the one that said she has mana problems and it’s cheap enough to let u take a health pot with u and another ward at the start fo the game which can make ur weak early game much safer.
Sorcerers Shoes – ok it let’s u deal damages a bit faster but compared to any defensive boots it also makes u deal them much shorter as u have to back of much earlier if u do not want to die needlessly
RoA – that is a very good item for Sejuani but if ur opponent zones u well enough to deny exp from u while not pushin’ the lane himself it’s “regen” passive will become nearly useless.
Iceborn Gauntlet – who told u it gives bonus damage for “Northern Winds”? o.O whoever it was, please slap him for me the next time u meet. Sejuani also has no need for all those early game mana spikes, there’s also only 30AP comin’ from it and because “Permafrost’s” slow is stronger (much, much stronger) it only gives u bonus 9% movement speed slow… yet another giant waste of gold.
Abyssal Scepter – this is ur only magic resist item, ok one rarely needs more than one high mr item but compared to “Spirit Visage” or even “Banshees Veil” that item gives u nearly no defense while bonus damages is more or less the same even though Abyssal gives u both AP and it’s own kind of flat magic pens.
Zhonya’s Hourglass – another non-HP based item and after u stacked so much armor (base armor, passive and .. ugh… Iceborn) another armor item even as big as this one provides u with nealy nth and that’s because there’s absolutely no point in getting’ more than 150-170 armor if ur skills do not stack with it cause the more armor or mr u have the less u get from every next bonus point so Zhonya’s gives u less than 5% physical damage absorption… so not worth it… also the fact that u need to pop it’s active shown how bad is ur build if u r in constant danger while playin’ a late game HPs based tank.
Banshees Veil – this one is a situational late game item for Sejuani and it’s finally sth that gives u some HPs except for RoA, but with how tanky u should be (with ur build, u won’t) u should not fear cc cause u can afford beein’ occasionally rooted in place and takein’ those more or less free damages, that passive is there to help u against AP have team when there’s so much … “things” .. thrown at u that u can’t dodge it all no matter how hard u try so that at least one spear or lux ult or any other insane range magic skill is “dodged”
Sunfire Cape – After re-improvements to this item and all the nerfs to Randuins how can u even consider it beein’ just a situational item and not the “must have”? u missed a big part in ur calculations or even did not do them at all. (btw, if u realy buy Iceborn and Zhonyas, then Sunfire gives u “whole” 2% physical damage mitigation @.@)
Warmogs Armor – this is simply a favorite item for the lovely WarThog rider – insane amount of HPs and regens that scale with them to help her survive early game so much more easily … one does not simply consider buyin’ it late in the game, one shall get it asap every single game.

“what to (not) do”:
honestly I can hardly with anythin’ u wrote there:
A. u can’t trade with ur solo lane opponents early in the game as Sejuani unless u’r playin’ against sm1 that has absolutely no idea what r his champions pros and ur cons which should not happen even in gold
B. Permafrost is rarely used as a defensive skill to “let u escape”, most of the time u use it in early game for early burst and mid and late game to give u more time to stick to ur target nd deal that DPS that comes from “Northern Winds”.
C. Sejuani’s combo is nowhere near Renekton in the point u tried to show as Renekton can instantly jump in and jump out dealin’ damages cause “Slice & Dice” let him reposition himself nearly instantly TWICE, while u have only the Arctic Assault to either jump in OR jump out, and “Arctic Assault” is a terrible poke as it’s the most mana drainin’ skill Sejuani has, it ;eaves u with no mean of escape except for flash when enemy jungler comes, it’s cooldown is pretty long, no1 has high HPs very early in the game and one always upgrades this skill as the last one.
D. u do not want to start usin’ ur teleport in the mid game it’s too late, cause as Sejuani u simply can’t win most 1v1 early lanes so u need to get ur gold somewhere else and u want ur bot lane to get rollin’ so that they can carry u in the mid game so that u can shine in the late game.
E. one does not simply go back to lane usin’ teleport, I know many pros do this in the LCS games, but they have both much better communication and vision in most games, while in yoloQ u leave urself with no means of healpin’ ur bot lane when enemies try to sneak dragon or get ganked by both jungler and mid laner of the enemy team which can be deadly for them if ur jungler is top even if ur bot lane allies r pretty fed.
F. 300 APs mean nearly nothin’ except for the fact u like to waste ur gold for troll build that may distract ur opponents a bit, cause (once again) Sejuani get’s much more damages (ok not burst but she won’t have high bursts damages no matter what) from stackin’ HPs. U can’t be consider a tank of the team if u’r HPs r more or less Graves-like.

English:
ok u said u’r sorry for mistakes cause English is not ur 1st language (so I’ll just get more haters for sayin’ what has to be said) but it feels like u made all of those on purpose cause there r so many mistakes in such a short guide .. use a translator or sth, I honestly had to read 2 of the sentences more than twice to finally understand what u mean :(

Iceborn Gauntlet OP. Let's say you have bought a Glacial Shroud and a Sheen, two fine items for top seju, I'll admit, and you have gathered 750 gold more. Yes, what's 750 gold? So yes, let's throw it away and buy an Iceborn with a useless for seju passive. It gives you aoe damage that scales with ad (you r not building ad), it gives you slow (wow->look your E), and it also gives aoe after each spell (wow-> then why not taking health or ap to get your W stronger).
The only reason to buy that item is because it offers mana and armor. And in my opinion it's like buying a Manamune to Lucian because he can stay out of mana and it also gives him ad. :|
conclusion: Just buy sth else. Or better, just buy that damned Sunfire Aegis instead of Iceborn since that is what you want- tankiness and damage (if I understood correctly).