1. I agree the party size is rather limiting, but I doubt party size really makes it a Baldur's Gate game.
2. Who cares what the shopkeeper UI looks like? Is the shopkeeper UI really what you remember about Baldur's Gate?
3. The reason you can give items away is to get certain NPCs to like you. A confirmation you're not being paid for what you're giving would be nice, or a separate button for gifting, sure, but is this really a "this isn't BG3" complaint?
4. Agreed. The game definitely needs a sort of shift-click to transfer in the inventory UI. Is this a "this isn't Baldur's Gate 3" complaint, though?
5. So you can swap to the next character that has not expended their movement and actions yet by pressing spacebar instead of accidentally wasting the turn of X characters because you hit End Turn on the first one. Is this really a "this isn't BG3" complaint?
6. Don't know. It's kind of annoying, and I don't think spacebar should choose dialogue options; it should only SKIP the voiceovers/animations. Is this really a "this isn't BG3" complaint?
7. This is nothing more than a visual representation of "what do I need to roll, considering all my modifiers, to succeed this check?" Is this really a "this isn't BG3"complaint?
8. RNG is RNG. Is this really a "this isn't BG3" complaint?
Overall, your list of complaints with the game, even if they were reasonable, were not actually reasons why this isn't BG3. This is just feedback on the game. Stop with the inflammatory titles and just call your thread "My Feedback." It would be much more accurate.