1. Only if you plan to have zero interaction with others at all. That includes buying/selling in shops, trading post, auctions, etc. People are nosy, all it takes is your name to show up somewhere at present for snoops to sniff your butt. Essentially RSing and flash games by yourself.
2. Still good to have your pets cached as a precaution. UCs are still money, wouldn't it suck to not take all steps possible?
3. While your account is a ghost account, you ought to also make sure the accounts you move the UCs from are as well. That includes if they're active or not, if they have active NFs, etc.