Quick question. I want to play with Open Cities Revamped and was wondering if quest mods are compatible if they deal with NPCs within cities? Or should I skip Open Cities completely?

Depends on the quest mod. Some need patches, others don't.

If a mod only adds dialogue to the NPC, then it isn't an issue. If it makes them go to a certain location, then you'll likely need a patch unless the NPC is being sent to interiors within the city.

...and there's lots of patches available. I currently have patches for Knights of the Nine, OOO, Kvatch Rebuilt, Clocks of Cyrodiil, Stirk.

There's also patches for Integration-TSL and Heart of the Dead. Probably Lost spires as well.

Heart of the Dead doesn't need a patch. The current version supports OCC and OCR natively.

Awesome, thanks. I'll just try them and see if my quests break, if they do I know to just disable Open Cities temporarily.

Have you looked through the http://www.tesnexus.com/downloads/file.php?id=32925?

Also, even if there isn't a patch to the quest mod you're using because it's new, or wasn't requested yet, you can always just use the hidden rock doors to get to the closed worldspaces long enough to do what needs doing and then exit through the gate as usual. The locations of those doors are in the readme btw.

Yeah I didn't even think of that. That's way easier than messing with my bashed patch.