Can't wait for the mod tools. The dnd community will go nuts and they won't need an expansion people will just start making full campaigns of thier own
I'd love to see more races and classes. Artificers, Tortles, Warforged, Tabaxi, etc. There's a bunch of missing subclasses too, like Storm Barbarian or Swashbuckler Rogue.
Maybe mod tools would allow that, but at the same time I'm not convinced. It just seems like easy territory for an expansion, sort of like Tasha's or Eberron... but for the video game.
They had wish in Baldur's Gate 2 at least I'm pretty sure. My memory is pretty vague but I think you could ask for a certain set of things and it would usually not end up how you wanted.
Wish was indeed implemented in BG2. You needed high WIS to get the choices that actually gave you what you wanted, with low WIS you got the poorly phrased dialogue options that were traps.
Limited Wish had two categories of wishes, repeatable ones and one-time wishes. Repeatable ones were mostly straightforward, but the one-time wishes had some sort of twist to them even with high WIS, such as wishing to be more experienced summoning hostile high level golems (that do, in fairness, award a lot off XP when killed).