Yeah, if you experience any bugs with the patch, most of them can be rectified by going to edit town, saving any households/buildings you have worth saving, then starting over, placing your households back where they were through edit town again.
One thing to note though: The patch won't work with most grocery store/shop mods, and won't work with ANY core mods I know of.
On the positive side, the patch is like a mod in itself. It brings, like you said, the ability to put stuff on your roofs, but also a couple other neat features such as an auto-fertilizer option. If you don't have any mods, the patch is TOTALLY worth downloading, if you have a lot of mods(like I did) you should consider it, and look into other mods, but overall, I think it's certainly worth downloading.