The light wallet doesn't do anything with TITAN to send or receive at the moment, and it will be a while before I consider implementing it. We need to solve several issues before we can seriously implement any TITAN in a light wallet. For now, even sending TITAN transfers is error-prone enough to distract from getting the core functionality of sending and receiving working, which means that it didn't make it into 1.0. I want to make absolutely sure this core functionality is rock solid before I build anything else on top of it.
And you're right, eventually it will store more information than is directly recoverable from the chain, at which point a more in-depth backup format will be needed. For now, though, the master password is all you need.