Weird graphical and non-graphical issues

[MarqFJA87]

I got an all-in-one installer for this game from myabandonware.com a little over a month ago, and it worked fine once I figured out how to use dgvoodoo, until it bugged out a week or so ago after I decided to pseudo-reinstall it in order to get rid of the opening company logo videos and unlock all the campaign movies. I'm not sure if that was the cause or if something had happened in between then and the last time I had played it a few days before that time (only thing I could think of is that GeForce Experience got a driver update during that interim period).

Now the game can't go higher than 1400x1050 despite the dgvoodo settings (and it's not even a selectable option in-game; the list of resolutions only goes as high as 1024x768), the mentat announcements and reinforcement timers are oversized, whenever every time I try to place a structure I get an advisory tooltip as if I never played the game before, the mission loading screen's briefing text doesn't appear if I'm playing from my campaign save (it does if I start a new one, though), and every time the game enters or exits a mission it briefly goes out of fullscreen. And the game CTDed once, but that might be a fluke; still, I mention it for comprehensiveness' sake.

I tried everything I could think of, but nothing works. Even a clean reinstall didn't do the trick, unless I missed something. For clarity's sake, I did accidentally install the game in a different directory when I tried that aforementioned reinstall; does that create some sort of duplicate entries in the registry or something?