You will indeed have to replay the whole thing after release, your experience and progress won't carry over. I would advise you to, when you replay, make some different choices and play a different class so that you get a new experience. I actually kind of prefer Solasta when it comes to combat, but one thing I can't deny is that BG3 does have a lot more going on when it comes to replaying. I would suggest you stop scouring everything you can and set the game aside until release if you're already feeling testy about it.
I also agree with you about the magical items. Not a fan of how they work thus far.
