I did the full sternectomy in 2005 and then had 28 radiation treatments when they discovered a Stage II thymoma. To me, the worst thing was the grating together of the chest bones when you stand up until they knit together (makes me shudder just to think of it!) Don't mean to scare you, it was only painful for me when I went from a laying to a standing position and only lasted about 7-10 days - I just wasn't expecting it and it scared me at first!
Just do what the docs and nurses tell you as far as the recovery goes - I was out of work for 8 weeks, partly because of the radiation. I could probably have gone back at 6 weeks without that.