My new Amiga 1200 arrived today! 
It works OK, as far as I can tell. It has Workbench installed on its hard drive. It has Kickstart 3.0; should I upgrade it to 3.1? Am I missing much with 3.0?
The accelerator is a Blizzard 1230-II. I know the version IV can be disabled at boot by pressing the "2" key, but this doesn't seem to work with this card. Is there another way to disable it? It runs very hot and I'd like to leave it off when not needed.
I tried loading some of my old favorite games from floppy... Many work, but some don't. Some have weird issued (keyboard not recognized, or mouse clicks off-set) while some just don't boot.
Some instead, show funny graphic artifacts (i.e. an intro screen with sprites moving around, the sprites leave "pieces" behind when they move - as if the previous frame isn't cleared correctly). Could this be a sign of hardware malfunction, or just incompatibility with the AGA chipset or the Blizzard card?
Is there a way to check the system (i.e. do a ramtest), and to check the system speed and performance? Preferably with Workbench because I have no easy means to transfer files from the PC to the amiga right now! 
Sorry for all the questions and thanks again!
Cristian
3.1 workbench isn't massively different, but there's some small tweaks.
As far as games running, two things to try:
Go into the boot menu (hold down both mouse buttons while booting or resetting) and switch display to "enhanced" instead of "best available"
When playing from hard drive, this is needed for some games, like Dune, Monkey Island and the Battle Isle games.
Download relokick and use that. This will make the vast majority of old games run just fine.
also, although it shouldn't be a big issue on a 1200, try switching between NTSC and PAL in the boot menu.
As far as file transfers... you absolutely want to get one of the PCMCIA compact flash kits. You can put it together yourself but I've been massively satisfied with the kit I got from amigakit.com