I'm an FDA medical officer (non-supervisory). I love my work, as it involves knowledge of clinical medicine, research methods, an evolving legal landscape, and business considerations of the pharmaceutical industry. (I work with developing new drugs.) There is a lot of variety among different physician positions. My recommended approach would be to submit your CV directly to parts of FDA that interest you. There are many opportunities for physicians to move around within FDA.
Hours are often a standard 40 hour work week. A few months a year I work on nights and weekends, because new drugs must be evaluated within a certain time frame. Pay depends on the number of years of experience, as well as the specialty in which you trained. I consider my salary to be competitive. My salary was about 140K 8 years ago when I started, but I am not exactly sure of what a starting salary would be now.
Links to some career information on the FDA website:
http://www.fda.gov/AboutFDA/WorkingatFDA/CareerDescriptions/ucm113289.htm
http://www.fda.gov/AboutFDA/WorkingatFDA/