Welcome to Texas!
As prior military, I can tell you the following tips:
Large metro areas require smog, GENERALLY smaller areas do not. If they do require it, it is 28.50, without smog is 13.50.
You can have your car tested in the county you live in, or ANY OTHER COUNTY if the other counties are smog-tested (you can't go from a smogged county out to a non-smog county and test your car, etc)
You can tag your car as out of state (TN) with a form at the DMV. you just go get your car inspected/tested and ask for a green form for out of state tags. the inspection place will fill THAT out and you take it to the DMV and you are golden. TN plates, and requirements.
As for tint: 20% in the front, ANYTHING IN THE REAR is allowed, 0% on the windshield, if below the A1SM level. Roll down your two front windows, remove the fuse and then inspect. It isn't illegal to have windows that won't come up.. it is illegal to have tint to dark IF they did come up. Tada!
