When people do stuff you don't want them to in your town just hit the wireless switch. The game will give you an error and rewind to just before you opened your gate. No harm done.
technically it rewinds to the last save point, which usually is the last time someone arrived on a train, left on a train, or right after you open your gates (before anyone enters).
Shit, I'll have to re-do everything ;_;
There was a 11 or 12 tile set I used, but found that about 4 of them I only used once or I was able to fiddle around to the point where they were unnecessary.
Sure, I have some unnecessarily squirrely paths or smartly hidden paths (behind houses, through foliage) to work within the 9 tile limit I desire (1 custom, personal pattern).
Also, replacing face-board and flag patterns (currently hanging flag) doesn't mess with the current pattern on a face-board or flag, so set and forget. It's too bad it doesn't work that way with custom shirts on mannequins.