I can't address your first two problems but software updates are done at the dealership but their rarely needed.

To update the GPS system you purchase the latest GPS DVD from your dealer and install it. I don't remember where the DVD reader for the GPS system is but you can probably find it in your owners GPS manual. I'd also guess that the dealer where you purchase the update will either show you how to install it or do it for you.

The GPS updates are not cheap though and it's worth shopping around to different dealers. I've seen them for as little as $75.00 and for as much as $250.00. Unless you live, work or travel a lot in an area that is changing quickly (adding new roads, road name changes etc.) It's not worth updating very often.