My thoughts:
Hell yes we should make Charge affected by Short Charge! We may have to modify the Charge skillset for this to be reasonable, but "Short Charge" not working with "Charge" was always really lame and unintuitive. We should absolutely take this change, and just complete the necessary design homework. Actually...allow me to do the homework, since I've been waiting for this forever. I'll assume 10 base XA, and 10 WP.
Left = Attack Up, Right = Short Charge
0ctr: 130, 100
1ctr: 160, 130
2ctr: 180, 150
3ctr: 190, 170
4ctr: 200, 180
5ctr: 220, 200
6ctr: 230, ---
7ctr: 240, ---
8ctr: ---, 300
9ctr: 270, ---
Yeah...Short Charge actually sucks compared to Attack Up (unless you're doing Charge+20). Very safe change. Except for the part where Noncharge C+20 Dictionary Calcs are BEASTS (like...we actually might want to talk about removing Dictionaries from Calc equips. I'm serious). The places where you might run Short Charge over Attack Up is if your attack is particularly low, or you have a Mime in the party, or your Archer has a magic secondary/you are a mage with Charge secondary. All hilarious and worth encouraging.
Teleport nerf...question: could we have two Teleports with different values? Like...a chibi teleport and a non-chibi teleport?
On the 20% nerf in particular: I've run a few numbers in my spreadsheet (average number of turns it takes you to move X squares where X is 10 or less). These numbers make traditional Teleport look slightly worse than Move+2, and chibi-Teleport look slightly worse than Move+1. (These numbers also ignore the "Fly" part of Teleport, of course). However, the decisions look less strategic in general with chibi-Teleport; you will sometimes take an 80% chance, on rare occasions take a 60% chance. Anything higher than that almost never has strategic value. You don't get the same interesting comparsions, where it's technically better on average to take a 7-panel Teleport than a 4-panel followed by 3-panel Teleport. In other words, the in-battle decisions just aren't as deep for chibi-Teleport.
Auto-Potion: this is bad because X-Potion isn't the most powerful potion relative to its point in the game. That would be Hi-Potion, which is a ridiculous amount of HP for mid Chapter 1. (I'm curious if we can go the opposite route, actually--make AP work with Elixirs when you have no X-Potions left. You'd only get to use it for like...one battle before you ran out of Elixirs, but it'd be hilarious).
Crit-move-up: Hm, maybe. The question on my mind is whether we want to make it an earlygame ability, or a lategame ability (i.e. something that could compete with Teleport/Move+3 on the right setup). I can totally imagine a setup that wants to knock itself into critical round 1...or centered around Reraise abuse. But it would have to have a GOOD bonus to make all that setup worthwhile. And you're likely not doing something that elaborate in Chapter 1 where you can't customize your setups to knock someone exactly into critical. That's the argument for the lategame version, anyhow. If we do go lategame, though, you're also probably going to want to add Regen back on to Chantage so that Chantage isn't just "I'm always in critical with absolutely no work".