So my LCD on the Galaxy Ace died and the back light was no longer visible, so I replaced both the digitizer and LCD using...

Its motherboard and CPU dependant, i'd say 16 on Mac Mini

You might be able to get away with putting it in DFU mode and restoring to the latest iOS. If not take it back to the man with no password and ask him about it.

You need to downgrade to iOS 3.1.3 (Requires no SHSH blobs) and using redsn0w or pwnagetool, make a iOS 6 IPSW that has the Baseband removed. Then put it into a Pwned DFU state and restore the baseband removed IPSW through iTunes. **If iOS 6 isnt supported by redsnow/pwnagetool, you may have to use iOS 5 blobs.

Remove apps you don't use.

6.0 Is the latest. There are no hints and suggestions to 6.0.1 being out soon. But that is usually the first update apple releases.