Peter,
Answers in red:
If the primer punch is rotated, it will probably rotate again during use. I know that from experience.
Well, that's discouraging. This is the third primer punch I've had. Sounds like another call to RCBS may be in order when I get off of night shift. I bet I can come up with a way to prevent the rotation IF that is the root cause and not a symptom. Some measurements with a machinist square and such should ID which it is.
It may occasionally loosen up also.
Some blue loctite should fix the loosening up.
Does your punch look like this when you lower the handle?
Not quite that bad, but off set like that before I rotated the punch.
If so take a picture of it and send it to RCBS. The lower sub-assembly is offcenter and needs to be replaced. My first one had this problem.
The lower sub assembly has been replaced once. I'm not sure replacing it again is going to resolve the problem, though it may.