[DanEC]

I didn't hear you describe anything that sounds like a crankshaft failure. Examining the distributor gear and pulling the pan to examine some rod and main bearings are the first things to do. But, you need to find someone who knows what they are looking at for the examination. Obviously if the base material is showing through on the bearing surfaces - that's pretty easy to ID. But, more subtle wear/damage may take a good mechanic to diagnose.

I don't think you have damaged anything by reving it to 5,000 rpm, unless it already had some fatal flaw in the build.

Valve train noise in these motors is not exactly rare. Is it a hydraulic lifter or mechanical lifter motor? If mechanical lifters, that plus header tube ticking will contribute to a somewhat noisy motor. Even with hydraulic lifters some of these motors (mine included) are never exactly quiet. If it sounds like a sewing machine with an attitude, it may be just fine.

2800 to 3000 rpm for fast idle on a cold start is definitely too high. Usually something down around 1500 - 1600 rpm is more normal. On a cold engine it probably isn't doing your motor a lot of good - don't know if it could be part of the problem.