Hi,
I do rely a lot on my IR cam, in particular for troubleshooting a device that lets off smoke or bad smells. You can easily detect shorted caps by controlled application of voltage and current on the supply lines. And many other things.
But I think it will be difficult to setup reproductible conditions. Some thoughts:
If you want to provide absolute values you must have a lot of expertise in thermal imaging, you must take into account environmental constraints like temperature and reflections of heat sources (lights, radiators), you must take into account fans whose airflow is usually altered when you remove covers. Often boards are installed such that you do not clearly see all components, if at all.
That makes a database of known good units a large endavour, and I doubt it will be that much useful for troubleshooting. To my experience, an overheating component is quickly and clearly visible among all others. Then its either the component that is faulty, or some other very close not restraining power flow.
BTW, I noticed that in many HP power supplies and some measurement untis the hottest part are the bleeding resistors across the capacitors in the power supply... :-/
cheers
Martin
Martin