1) If you don't have anything added or modified to OOTP other than a saved game then all you need to backup is the saved_games folder and plopping it back in to a reinstall won't be a problem. If you've added or modified files though then you'll probably want to backup the entire OOTP Baseball 10 folder (the one that holds the saved_games folder, for Vista it's in C:\Users\[username]\Documents\Out of the Park Developments\OOTP Baseball 10). If you've done any skin editing then you may want to backup the same named folder that is in the Program Files folder. Maybe at least copy the receipt.txt file in that folder.
2) Just contact your
licensor. I don't know exactly all that they need, but give them the new and old email addresses, the game and version you got as well as even the order ID if you can easily find it.