If it is too much stress to have the roof done, then don’t do it. You might want to get some estimates on what it would take to replace it. That way you know how much to allow for having the roof done when you start negotiations with prospective buyers. You’ll want to discuss this with our agent as well to let him/her know that you’ll not redo the roof.
The kinds of things you’re talking about doing are the kinds of things we did to our old house. Our roof had been completely redone in 2008 after Hurricane Gustav. We had just put in energy efficient windows earlier in the summer before we decided to list it. It didn’t necessarily add anything to the list price but it was definately a selling feature.