Do you speak Thai Johannes? A lot of Thai mini-soaps (of which the TV is crammed) use farangs as cameos sitting in restaurants etc - usually acting obnoctious and loutish, unfortunatly (and we wonder why Thais sometimes have a bad view of us!). If you don't, then it most likely you will want a foreign agent who can put ou forward when western movies etc are made here.

I'm not sure how much talent scouts are used here - a lot of important people's kids become actors and models - there is a lot of neopotism and familial deals here.

You will need to fnd another job I would have thought to get that Work Permit as otherwise immigration/labour would want to see paperwork from your employer and it would last as long as the film.