1) Yes, Cynanogen Mod is basically empty. You'll need to install the GAPPS zip file. Get it from their website.
2) Wipe Data, Cache, Delvik Cache and System.
3) If you made a full Titanium (user apps + all system data) then your contacts and such are backed up; however (and this is very important) TitaniumBackup has issues restoring system files when the ROMs you're using are different. If TeamSeven is Sense-based, for instance, a lot of system files will not work with Cynanogen Mod when you restore using Titanium Backup because, well, the systems are different. It also happens when you're restoring backed up system files from 4.1.2 to 4.2.2 or 2.17 to 2.24, if you know what I mean.
Use third party applications to backup contacts, text messages, call logs and such.
Call Logs Backup & Restore
SMS Backup & Restore
I use those - they're free on the Playstore.
As for contacts, mine are already on GMAIL so I use Gmail to restore. I am sure there are applications on the Playstore to backup contacts, though.