Good to know I'm not the only one. So maybe someone will find this thread and know what to do.
@ModerateOsprey That was actually among the first things I tried, and I also bulldozed the lot, changed the lot type, et cetera, but nothing worked. Even when I change it to a public lot, the lot symbol replacing the plumbob remains too high.
I'm going to try one of those custom map replacements, then change it back and see if that helps with the smudges at least. Now, let's see if anyone actually made one for Granite Falls...
EDIT: Didn't work. The smudges aren't visible (or at least not noticeable) on the replacement map, but when I change it back to the default map, they're back again. And the plumbob issue wasn't affected at all. Then again, I might just keep this replacement map... Just look at it, it's super awesome! <3
https://abload.de/img/ts4_x642022-06-1317-50kkz3.jpg
(
This is where I downloaded it, in case anyone is interested.)