It has a 32-bit ARM processor, which has a secondary 16 bit mode. It is capable of running in 32-bit, but it almost never does. So it is both 32 and 16 bit, in a way. But it generally runs in 16 bit.
The tool extracts everything except modulation at the moment. It's not perfect, some songs desync badly, and some voices output aren't 100% right, but it's generally very good. I'll link you to a preview version when I get home, if you want.