Registering A Bike

Hello all

Buying a 2nd-hand Honda Wave from a friend who is leaving LOS but who has company here.

Bike is in name of Bkk-basedcompany and has Bkk number plates.

Company is selling to me & we plan to register bike in my Thai gf's name.

I do not currently have residency, but neither has my Thai gf, who despite having lived here 7+ years still has her residency registered in her Isarn province.

Neither she nor I really can be bothered with residency.

2 questions:

1) can the bike legally be registered in Bkk with the current number plates if owner is does not have residency? Or would we have to go to the office in gf's province?

2) how likely will police be to try and extract money from me if they see the bike ridden in bkk with owner not from bkk and not even being me?