If I do a restore with cwm, should I wipe the cache or anything like that?
As far as I can tell, it makes absolutely no difference.
Your cache (wiped or not) will be overwritten with whatever is in the nandroid backup you are restoring. This makes it quick and easy to switch roms at will, using previous backups.
Having said that, I usually wipe caches -before- doing a backup, just to save a few mB of storage space. That is mostly inconsequential, though.