Sounds like your demise is coming sooner than you think. Take a few para and wash them down with several pints of the black stuff on paddy's day, wouldn't be to worried about overstay or winter home in the future. Ide say you may be departing thailand in a casket!
You can't do tattoo work in thailand legally, reserved for thais only (like hairdressing) i think ! You can run a buisness or buy into one, but iam sure you would be cheated and loose the lot.