Balance and difficulty.
I've made my thoughts on AC/HP/etc known in other forum posts. In summary, I would be happy with all of your suggestions 1.1-1.3 (I suggest that HP shouldn't be changed significantly; if AC is changed then STs need to be similarly changed)
1.2: In this "subtract disadvantages from advantages" scenario, what if you have 2 Advantages? 3d20 pick highest or normal Advantage?
--My suggested solution is to make height/backstab a flat +1 to +5 bonus that stacks with other flat bonuses. (I suggest +2 or +3)

1.4 Larian, as the DM, is allowed to change monsters. However, they should make less monsters with disengage jump abilities (spider, minotaur, bulette) because this invalidates the role of tanks/frontline fighters

2.1: I'm fine with tadpole rolls being auto successes, with the assumption that something actually bad will happen to us if we use it too much. If there is absolutely no consequence (and in fact, more benefit in that you get more story and you dominate others' minds) from using the tadpole, that's bad. Cost-benefit/risk-reward is important.

Battle mode, movement and interactions changes.
1.2 Currently the game automatically has characters stand up, using half their movement. EXCEPT if you fall over during your turn; in this case your turn ends. A fix for the latter is much more important than making the former manual instead of automatic.

1.7 As far as I know, climbing ladders does not cost any movement??

I either strongly agree with or am not opposed to the rest of your suggestions from your past 3 posts (the ones I've read). Good feedback.