Spectacular analysis and good advices! - Helping up a downed character often makes party invincible. And stabilizing is indeed the most canonical alternative in D&D mechanics. - There was formula in old BG games: character level*100gp=price of ressurection. Can serve good to BG3 as well. - The absence of restrictions on long rest is deeply embedded in the mechanics of storytelling. While I understand your reasons, I truly can't see the way how it will be possible to change without massive losing of content. Not only secondary plot of companions but main plot as well have deep integration into the current mechanics of long rest. - Can't agree more about Potion throwing - it's completely devalues casting healing spells. - 'Only allow changing memorized spells at camp when Long Resting' A, good old days of 3.5 edition.
The other points are also very reasonable.
On my own, I want to add that the growth of experience is going too fast. For scientific purposes I slowed Exp progression for 20%. If earlier I had the maximum level at the beginning of the third chapter, now I have the tenth, which feels more logical. In addition to the fact that there is room to grow, quests become even more valuable.
