I did not read everything above but:
- It is normal for every RPG I know that you swim in money sooner than later.
BG1+2 had the advantage that shops have some good unique and expansive items so you spend some time gathering money to get all of them.
In BG3 you can get almost everything at once and I agree that the huge amount of "junk items" is part of the problem.
- They should quit those DOS1+2 mechanics:
+ you give stuff for free to merchants to get better prizes.
+ killing the merchant will give you EVERYTHING you have ever sold him
instead they might add
+ maybe bring back DOS2 rule that you can steal only once from each NPC (wait a sec, I really suggest adding DOS stuff in a DnD game
+ Prizes should not depend on who talks to the merchant. Switching items between characters before selling is just annoying. so maybe
- All chars pay the same prize. The prize should be fixed. Maybe they change prizes if you do quests for them or how much their faction likes you
- If the merchant hates one of your party members you have to keep them in camp to trade with them
Edit: crap, the text ignores spaces before the text.
So you cannot make a table where one point has several sub points