Marlou, welcome to HealingWell!! 
You've certainly come to the right place for some questions and answers!
I can imagine you being worried about age, that's many times a factor in any surgery. However, sometimes it doesn't seem to matter. My Grandmother had a bypass when she was in her 80's! She lived a good many years past that into her 90's and had quality of life. That's important when making these decisions.
We have a complete thread here on Pericardiectomies and if you haven't already read it, please when you get the time, go ahead and read what you can!! It comes from real people who've been there before and came out ahead!! We actually have a Pericardiectomy and then Pericardiectomy II thread, since we have numerous members here that have gone through it already, or are planning to go through it soon.
As far as them fixing your other arteries when they're in there already, it makes sense to me. I've already had two stent placements, angioplasties and a triple bypass this past Aug. 2004.
I know you are worried, after all, who wouldn't be? This is a very big step for you or anyone to go through!! Just know we are here for you and please ask any questions you like, or vent as needed. Best wishes to you, Marlou!
Hugs, Teri 