Random pains in legs ankles feet when sitting or standing for couple of minutes, no pains when moving around. Is this nerve or circulation related?

See rheumatology. This is not classic for nerve or circulatory problems. I would see a rheumatologist who can evaluate the problem and get testing.
Hard to say. It is not really classic for either. Restless leg syndrome comes to mind. Consider a check up with your primary care doctor is probably a good place to start.
Maybe nerve. Since there is no pain when you are walking and moving around, that is a good thing. Pain when walking is a symptom of poor circulation. Nerve pain seems to be prominent when at rest, be it sitting or trying to sleep. Musculoskeletal pain is typically brought about by use and function. Though arthritic conditions can have pain on first use, then dissipates after further motion.
I do not think so. The nerve issue or circulation problems will do that, try to do some exercise and see if will take care of it.