Your skill order and pros/cons section need some work. Maokai's Q is pretty weak in terms of damage, both base and scaling. This is even more evident in lane, where your saplings and Twisted Advance really shine. Sapling Toss is amazing for some many different uses. I won't go into all of them, but in lane, specifically, use them as an incredible zoning tool. They're simply too strong to ignore, and you can force people into bad positions. Arcane Smash's range is pretty short, so harassing with that is not only harder, but much riskier, not to mention weaker than saplings, and has less follow-up potential. I always max Q last on Maokai, especially in a lane. Some people will argue that the scaling slow and higher base damage than saplings justify maxing it earlier, but as I said before, saplings have so many uses, and Maokai's not about dishing out insane damage. I would also argue that the slow is fairly irrelevant since you're most frequently gonna use your Q for the knock up following a Sapling Toss > Twisted Advance initiation.

There's a sentence about "Maokai can carry the game by himself." This is absolutely untrue. Even with his 80% and 100% AP ratios on his W and E, respectively, there's no way he can deal enough damage to carry, unless the enemy team is ENTIRELY comprised of squishies. He has almost zero DPS (not to mention high CDs which further classify him as a burst champion when it comes to offense), and he's more about his insanely powerful CC and utility than he is raw damage. That being said, as mentioned before, Maokai does have very good AP ratios that should taken advantage of, just don't overestimate your power.

I realize that this guide hasn't been updated in a long time, but if you ever do come back, don't give up. There's definitely some work that needs to be put in, but this not a failed guide by any means. Maokai's intended role upon release was to be a support, and while this doesn't make him an amazing one, don't listen to the "Maokai's an unviable support" comments. Sure, this would be a niche guide, but that's exactly why it should be improved. The need for interesting, unique guides is far superior to having a bunch of people telling you to do the exact same (or very similar) things.

I would vote but things seem a bit incomplete, I would like to see an items explanation chapter because I was confused about things like Targon's early game and Talisman later...? I know you just answered this in the comments, but readers should not have to navigate to the comments page to get answers.

I like your ideas, but I'm not seeing a complete representation of them yet and as such cannot upvote.

Regards,
Teyso

Perseverance is getting nerferd to hard this patch... I dont think its worth getting it anymore... the MR masteries are so underrated :(

and targons is nice cos you can get the money even when you are not in lane... and thats whats this build about... about roaming and getting all other lanes rolling. Thats why you should buy boots early on! you are simply ignoreing that fact... roaming, all about roaming!

and btw I swap targons for talisman later on... but you would have way too small income with it early on :(

and sure CDR is nice on maokai but I believe mana reg/summoner spell cdr is worth to skipp that 2 points cos 0.3s on Q; 0,65s on W aren't crucial

The item build is terrible. Never get boots that early, especially tier 2. You should finish sightstone and either targon's or glacial shroud first. I personally wouldn't use targon's at all (talisman is better) but that's up to you I suppose.

CDR is crucial on maokai, you should take Sorcery in offense. You should be taking the masteries Perseverance and Second Wind rather than the MR masteries.

I would stick with 3 movespeed quints to make up for not buying boots early.

This is all ignoring the fact that maokai is not a viable support whatsoever, but if you were to use him as such, this isn't the way.