1. Each games has it's own OS requirement. You are allowed to use a newer OS as long as it is in the same OS family. For BB2 games, there are 2 OS families, it will be either H9.xx or H13.xx. The game will use one of those, you must use at least the version required by the game or newer, but you must stay within the OS family.
2. No way to save progress on those games, as soon as you cash out, progress gone. So if you want to keep playing to open all the games, then you can never cash out. You can power down as long as you have credits and hope your batteries don't run out. In the casinos, these games were connected to a WMS central server that saved the player profile, as you cashed out, it would print a ticket which you could then use later at any machine that had the game.
3. On a BB2 there is no SSD slot, it only has SATA ports which could drive an SSD or a hard drive used to store the game that is copied from the CF card when first installed. It was done that way so when the game operated, it could load things off the hard drive faster and not create pauses during load times from the CF card.