@nickibitsward and @starguru , thanks for your help about the bulldozed building thing. The tip worked.
As for the transparent doors/windows, I found that it was only that specific lot that had the problem. It's marked as a festival lot atm, could that have anything to do with it?
Anyway, deleting my caches didn't change anything. As for the tomb part, I had not done any tomb building yet. No links or triggers or even tomb objects were on the lot when the problem occurred. Basically, there was no association with a tomb.
The mod part: Rather than do a total factory reset, I decided to try just taking out my folder with mods first, and sure enough, the game is normal with the mods gone. Seems I'll have to do some purging and find out which one went wrong. The game works with CC, so it's definitely a mod problem. Thanks for your help with that issue.
Now all that's left is the weird transparent door thing.
