iPhone 4 problems, please help

Just got an iPhone 4 from my dad and im trying to restore it, i want to delete everything and start afresh, but i want to stay on iOS 5 because im waiting for unthethered jailbreak, i don't want to update to 5.0.1 because i don't want to wait even longer for a unthethered jailbreak.

So iTunes refuses to restore to iOS, dont know why, one thing which is p*ssing me off.

Second problem, i have some apps which i want to keep so when i try to sync so i could transfer them to iTunes,k it refuses to because it says im not authorized for it, even though i have selected authorize this computer.

What to do?