We are doing it a lot at my oufit at the moment due too many Captains and not quite enough FO's (long story but a union deal limited the scope for demotions due over staffing). I find it no problem at all and never have done, it's almost always a nice easy day out and a chance to chat with guys you don't see that much.
in the right seat my hands seem to be all over the place and I'm just not COMFORTABLE.
I would politely suggest that you should feel comfortable, you are an experienced, professional airline Captain. If you don't feel you can handle being PNF and P2 in the right seat of an aircraft you have 3000hrs in command on then something is a little amiss. Get on with it and be thankfull the company doesn't solve the problem by demoting you or some of your more junior colleagues.