Alright, I didn't have much time before but now, after looking more carefully, there is more matchups I dissagree with:
1) Fizz- he can be tricky as long as you don't have correct runes, you take bone plating in second tree, that prevents him from all in pre 6 and winning it, after 6, if he engages with his ult, you wall him behind, then he has to jump on you, and you can quickly q+e+r/aa to proc phase rush and run away, to win first levels you take 3 corruption potions and tp, so he can't outsustain you because you basically stack first 3 waves and push it, then recall and tear or help for jg with crab.
2) Cass- just like you said you outrange her, that's why anivia wins in burst trades, q+e+aa and phase rush, after 6 you can easily kite her with your ult, the key is to dodge her q, but since you outrange her you should be able to dodge most of her q.
3) corki- he might save his dash but don't forget anivia can stop his dash with her wall, if she manages to do that she will win in early
4) lux- no extra ms, no dash, the true is that she outranges you but eventually you can clear waves, and outscale her with much better kit,
5) sylas- extremly easy, phase rush and 3 potions, just like with fizz you stack first 3 waves, you can easiy kite him, its one of my favourite matchups,
6) tristana- her dash can be stopped with wall, you lose first levels but eventually you can os her the longer the game goes, just like syndra vs lucian( with the diff you need to wait propably till lvl 11), you can avoid laning by pushing wave with ult and roaming to that time
7) diana- 3 potions, same tactic what with fizz, or exhuast and doran,and just like i said, cc is a threat and she doesnt have much sustain early on thats why you can easily survive
8) galio- his dash can be stopped with wall and you never should be in range of his cc, on top of that his ult also can be stopped with your q or wall,
9) katarina- one of the easiest matchups, her ult can be stopped by either your wall or your q, same tacticwhat with fizz, stacking waves and denying her cs, cause stacked wave is under her tower, she cant take it all, 0 cc so she cant stop your ult, she doesnt scale better than anivia, to lose you need to miss q, but with some games you notice when you can use q that she cant dodge and when you cant, also early on after she comes to dagger she doesnt get 100% reduced cooldown so you have 1-2 sec you can hit her with your q
10) malzahar- only threat is his ult, but you outrange him so he needs to flash, if you follow jg correctly he cant kill you, rest of his kit is just worse than anivia's and anivia outscale and outranges him in general, also he wants to perma push but anivia pushes faster than him by killing his (w) with her ult
11) akali- just like i said earlier on
12)azir, outranges you, pokes you down, and makes pressure with his ult, can easily dodge your combo with his combo w+e+q( for longer range of dash), he scales also very well, i would say its equal matchup
13) ekko- I meant his stun but like you said only threat.

You made a mistake in your text as passive(egg) needs 6 not 8 seconds to rebirth
There is also more options of runes imo, basically for second tree everything can be played, depending on enemy team you face, i use to flame more tanky anivia with green tree in second

that's all i have noticed so far, take it as an advice and ask if you disagree with sth :)

TACTIC WITH 3 POTIONS- it bascially is all about starting with corruption, giving you sustain, most ppl in low elo run ignite on ***asyn and it gives you opportunity to poke them down, and then recall after third wave, or hard trade back of, recall tp at lane and basically outsustain them. + corruption works very well with tp as your stacks are insta restocked