I ended up reinstalling the game. This time I followed this guide
instead. So far it is working much better.
Basically, he has you install EasyTutu which includes the bug and text fixes referred to in this thread, but it also runs BG1 on the BG2 engine. This means it will use the BG2 GUI as well, but you can install Original BG1 GUI
It will also use the BG2 paperdolls and shield animations, which you can fix with 1PP
. The components you need from 1PP are "Core paperdolls," "Extended palette entries (compatibility install)," "Legacy shields" and "Core updates and item patches." Core paperdolls will restore the BG1 paperdolls, and legacy shields will restore the shield animations to match the paperdolls. (Extended palette and core updates are required.)
Just make sure you install it before
the widescreen mod. I've got it running at 1280x720 and it is great.
Edit: Just realized EasyTutu will also use the BG2 thief animations. To fix that install the "Female dwarves" and "Thieves galore" components from 1PP. (Female dwarves is required by thieves galore.)