Sorry, I've been loaded with work, I'll answer your questions as best as I can now.
The Orginal Teen Titans have left and will be long gone by the time the heros get home.
Titans tower is underground in this RP, to help hide it. It has a super computer, with access to police records, criminal profiles, and pretty much everything the internet can offer. It also has a decent sized library, gym, and power training rooms, all to benefit the heros. I'm also planning on adding a surprise in there for later.
The villans have multiple bases, but none as nice as the Titans Tower.