Tyke re 'parthes' - is your tongue in your cheek?
This pronunciation of 'paths' isn't unusual. It is, after all, Received Pronunciation which hasn't yet been laughed out of court. RP would, however, keep the short 'a' in maths just as it's short in mathematics.
I and many others say 'barthes' for baths and even Newcarstle.
I'm all for regional variations and disapprove only of those who try to change their natural accent for effect.