what is normal for a paint job

Just about every manufacturer requires 2 full coats of clear. Remember the clear is the UV protection.

If your clear gets thin, it will fail and start to come off.

Like mentioned above, this is why, if you plan to fully cut the car, you want more than 2 coats. 3 coats with one being a sacrificial coat for cutting is common. 4 would allow the clear to be worked even more.

I have seen as many as 7 coats of clear applied with most of it ending up on the floor through blocking of the clear to achieve an absolutely perfect and flat surface.

X2. The straighter the bodywork, the less primer you need and the less time needed to sand and block it down. I work at a shop with many insurance company contracts. We typically shoot two coats of base, and two coats of clear, sometimes three. We sand down the peel enough to match the factories. If you want a show car glass-finish, you'll shoot more clear and spend a lot of time working to achieve that....a practice of diminishing returns for the dollars spent if you ask me. But that's my opinion.....