Give me a minute to reread everything you're asking and I'll help you.
Edit: Tell me if I get this right.
-You are on 2.2.1 or some version of Froyo
-You want to update to a newer version of android and liberty
?
If that information is correct. Backup everything you have on there you want to keep. Use titanium backup for USER apps, move any pictures you want to keep to your external card or to your computer or something and make sure your contacts are backed up through google or something similar.
Next you will need to update/SBF to .605. The easiest way to do that is here
Linux solution to your Windows/RSD lite problems Make sure to use the (4.5.605 Gingerbread) file. Instructions are listed in that thread.
Once you are up and running on GB .605 you can proceed to install Liberty. The latest version is Liberty 3 v 2.0.