I waited 3 weeks for my certificate to be sent to me and it only lasts 30 days. The agent will get you the certificate on the same day giving you 30 days to use it
Depends what you are looking for. New buildings are mostly studios less than 30sqm. Older buildings can provide more than double the space for less money
There is no safe, legal way around this unless you have a Thai wife that can be on the title deeds. I think there has been a big crackdown on this on Phuket in recent months and the rest of Thailand could be next. Really wouldnt risk it unless you can afford to lose the house