Yes, the Testors Lacquer has the durability, no problem there.
Your auto clear would probably be more so, but a little more work to get it sprayed. With the Testors, you have the option of spraying from the can, or decanting and spraying from your airbrush.
Future, yeah...wet sanding would take it right off, as Future is an acrylic gloss, and the water would dissolve the Future, which is why it was probably all right if you dry sanded it. The thing with Future is for a gloss coat (if you are using it to make a top gloss coat for a car, if you are just using it as a gloss coat for decals to adhere to, you don't need to be as careful)...multiple thin coats is the key. The first 2-3 coats are most likely going to finish looking pretty flat and pebbly. However each successful coat will fill in the flat, pebbly appearance, and after 5 or 6 thin coats will look as good as any lacquer gloss. The final coat you "flood" it on a little more. Meaning, drop your air pressure maybe 5lbs, and slow down on your air brush pass, it gets a little more product on, and looks like it is "flooding" the surface, and you can almost immediately see a shine in it.
Having done one car with Future however, I personally would stick to the Lacquer clears like Testors.