1. I'd love an option to create my own, custom 4-person party. Even if it means missing out on a lot of story. I want to make my own party of drow, or dwarves, of the exact alignment, subclass, background, etc that appeals to me. I hate that, if I want a cleric or fighter in my party, I have to use pre-made characters who disapprove of most of the things that I do. And, if I want a life domain cleric, I need to roll it as my main or do without. There are so many party combinations that are inaccessible due to only being able to create one character. Baldur's gate 1 and 2 allowed this option. The pre-made characters thing was something I was not a huge fan of in D:OS2.
2. BG3 has too many items in the game. I don't know if everyone feels compelled to search through every barrel and crate as I do, but I don't want to miss anything important. The items are worth significant amounts of money, too. So my main character is always getting overburdened, then I have to spend time moving items around to other characters. Then when I pick up something important, it's hard to even find it in this huge, messy inventory. It was a major weakness in D:OS2 and, honestly, in BG1 and 2. I wish you guys would address it.
3. BG3 has too many treasure chests all over the place filled with mostly junk. I'd prefer treasure chests to be rare and contain good stuff. That'd be a lot more exciting. Right now it feels like a chore to check every chest and pick up the 11 gold and heavy loot to sell to a vendor. The hidden chests in D:OS2 were super cool when I first started finding them until I realized that they never had anything good in them. In D:OS2, act 1, there was that secret area you teleported up to to find a strong 1-handed sword on the ground. That was cool. Figuring out how to teleport chests from hidden locations would have been exciting, except when you opened them, they'd have a trap disarming kit and a scroll of rain. I'd prefer less chests with more exciting loot.
I love the 5e rules, and I'm really enjoying the game.