To differentiate Titan perhaps a bit of Growth on the armour? Something massive and worthy of the name Titan.
For earth force I direct you here:
http://www.freedict.com/onldict/swa.html
When in doubt find a cool sounding, but appropriate, word or phrase in an appropriate foreign language. Swahili came to my mind first.
For Speed Demon don't have a Super Hero ID - have the guy go public for better name recognition. If you have to have a then take a que from your first post and call him the Screamin' Demon and tack a roaring sound as a special effect onto his running (he is a running speedster, yes?) and perhaps a small flame effect as the kinetic field that keeps him from going splat at high speed gives off the heat build up from all of the KE. Doesn't do any damage, just looks and sounds cool and leaves openings for improved presence and sonic attacks later with XP.