1) attach USB your nuvi to your pc ,enable hidden folders in Windows
[Only registered and activated users can see links. ]
and delete them (backup old maps and .unl and .gma first on pc)
2)All compatibe maps you can see in Garmin product page under tag "Compatible maps" :
Code:
Please Login or Register to see the links
3) I think no, traffic should be included in Nulink! service as shown in product specs: tag "Specs" in the above linked page