Kal,
>My question is this; is there a comfortable way to hang, sitting on an office, swivel-type chair?<
I did all of my hanging in an executive type office chair. You can hit all angles between OTS down to BTC. By scooting your butt backwards or forwards, adjusting the position of your pelvis, you can hit almost any angle. For OTS, you will need to use a rope extension. For SO, the hanger can be almost on the front edge of the chair, with the strap and weights over the edge.
You can also easily hang OTL or UTL while sitting. Use a folded towel between the hanger and your leg.
With almost any angle, hanging while sitting, you will need to adjust the amount of weight to allow for friction. Except of course for BTC. With BTC, there should be little if any friction.
Bigger