Can’t give you an answer to your first question and only an anecdote on the second question.
I spent two years in ROTC at OKState before I left on a knee injury but we got a special brief by an Army SF Major who had some command experience in Afganistan and he seemed to really enjoy his work. He had some really interesting stories of working (negotiating deals) with the Northern Alliance leadership.
As far as the third question goes. The SEALs along with Army SF, Rangers, Nightstalkers, Delta, PJs and the like all work for Special Forces Command which is a tool used by other Force commands (CentCom, PacCom etc). Those in command were originally one of the combat arms and not a supporting unit.
Do these commanders work in an office? Yes, but all of them have combat training and a high probability of combat experience. Good luck and God bless. I hope this was some sort of help.
Well, if you really want answers to this, you might want to go check out this site http://www.thesealquest.com/ Pretty much the place to go for all things SEAL related.