Tank, I don't know who's fault this was but from the outside looking in.... It sure sounds fishy. How could you not smell coolant? It has a very distinct smell to it.
Also, blowing up a motor doesn't necessarily fall on the person's shoulders that built it. I could jump in a fully built car and blow the motor. Does that mean it is the fault of the builder?
Knowledge is your biggest enemy right now, or therefor lack of. I would do a shit load of research on the Supra and then try rebuilding it again. I did research on the Evo forums for about 2 years before I even bought the car and started building it.
Don't expect it to happen over night either. Building a high horsepower car takes time
So, let me understand this a little better.
1. Speedometer doesn't work?
2. Temperature gauge doesn't work?
3. RPM gauge is off by as much as 1500 rpms?
4. Tranny doesn't won't allow it to go over 119mph?
5. Limited by the gear?
I'm not taking sides, but it sounds like you were too stuck on buying parts to make your car "go fast" rather than buy the parts to fix it and monitor it.
Sinking all that money into a car without being able to monitor things like temp, rpms, and egt's is dangerous. Thats just asking for trouble.
Hell, I don't even trust the stock temperature gauge as they can be off as much as 60 degrees. I learned my lesson in a previous car when the stock gauge read everything was normal, but the aftermarket gauge read it was running too hot.
..and as far as the funny as remarks in this thread.

I almost peed myself.