1) PAB doesn't work on a P2 its a P3 only feature since the P2 can't support the PAB bus. The P2 doesn't have the 'ooomph' to use the PAB possibilities
config from 4 to 5 must be redone completely.
2) the settings can be restored if you manipulate some values and import the values ( other ppl might know which ones you need to look for)
3) you can go the latest and greatest in 1 step , ( don't forget to update to the correct PLC)
4) read 1 again.