BGT has been tried many times and works, as you can see from very recent threads on our forum. Installing it is just like anything else. 1: install the game and whatever you want on top; 2: point your gemrb config to the game dir; 3: profit. It doesn't matter when you install gemrb, as you usually wouldn't do it into the game dir.
IA hacks the exe, so that would require extra work that hasn't been done yet. No female dwarves for you, the files would lay there unused unless you modified their lines in avatars.2da (bgee implemented something similar). Simple, but you have to know where to look. The few new animation types would need to be coded in the engine, but the rest of the mod could easily be adapted to also mod our dehardcoded files directly.
I'm sure there are normal mods that don't work too, but that's not how it's supposed to be and we fix issues as we find them. The original games didn't exercise all areas of the engines after all. SCS could easily be broken for example.
10pp will mod the lillies out of scripts and dialogs, then recompile them. It extends object.ids, so weidu works normally, but my guess for running in the original would be a crash. If you mapped the extra pc objects to existing ones, that would be fine for most uses (teleporting around), but would give you extra xp in other cases. Like I said, it's pure weidu and perl, so nothing gemrb specific.