Is it appropriate (legal) to request practice instrument approaches in IMC? I have always requested practice instrument approaches while maintaining VFR (with a safety pilot or instructor). But I was wondering if there are any issues (legal or otherwise) with requesting multiple approaches in actual weather at the end of a short IFR flight. Assuming, there are no safety or controller workload issues. In other words, assuming weather is well above minimums and controlling facility is not busy (during off peak hours). 

I realize I could just make multiple missed approaches, and get the extra approaches that way, but that is not what I'm asking.
Certainly you can request practice approaches in IMC on an IFR flight plan.  ATC will accommodate aircraft on a first come, first served basis. It is legal, and appropriate if ATC can accommodate it based on traffic (or noise or NOTAM restrictions).

Of course there will be some difficulty if you attempt to do practice approaches at Los Angeles (LAX) or New York (JFK). ATC would not likely accommodate this at these or similarly busy high performance aircraft airports. But again, unless it was otherwise restricted (e.g., noise abatement requirements or NOTAM restrictions) you can certainly request this type of IFR/IMC handling.