I live in Salzburg and know about Fucking - never been there...
but I can deliver a litte explanation:
Fuck comes from Fock and is a dialect-word for Pig.
In that region it is very common to have an ing-ending on village-names.
200hundres years ago this was probably only a pig-farm or a region where pigs were farmed...
but I have no idea where Petting derives from...
