I'm not really sure about most of your questions, but you should know that the most capable of the SNES emulators for the DS, SnezziDS, will only run on devices that have GBA support. There's still SNES DS, which is old and uses the far-from-perfect SNES Advance graphics engine, and SNEmulDS, which isn't fullspeed yet and has issues with many games. SnezziDS has its flaws too, but I would consider it the most advanced of the three. Sorry I can't answer more of your questions though.
Bookmarks