no
The best emulator is NO$GBA
emulator-zone.com visualboyadvance is the best.
A GBA or NDS, but I think you should use No$gba emulator, it works with both...
Use Google to search for NO$GBA it's an emulator for both DS and GBA games.
One of the best GBA emulators on the market is called No$GBA it is highly ranked. It is advertised to be able to play many types of games on this one emulator.
emulator.com
brothersoft.com
You open and play them in an emulator. The best GBA emulator is Visual Boy Advance. http://vba.ngemu.com/
if you mean a gba emulator (gba = gameboy advance ) the best 1 is vba (visual boy advance) and you can get rom's for it on romulation.net
No, you can't because it is a GBA Rom. You can play it on the computer using a emulator. A good GBA emulator is the VisualBoyAdvance.
No, you cannot get a GBA emulator on the r4. Nor can you on any flash card. However google eZFlash, it's pretty much a flash card for the gba slot on the ds.