" Would it be hard to repair these roll resistors and/or tranny/engine mounts?"
It is not easy but a few of us have done it in the driveway (hands up!)
"Do you have to pull the engine?" No, no, no, no, no.
"If you were looking for a budget car and a '99 Mystique w/115k miles was for sale for $2k with possible motor mounts/roll resistors needing replaced(otherwise good), would you get it?"
In a heartbeat.
"Would it be a rather "simple" fix? My dad & uncles know some things about cars ....."
For them, it should be.
"Could get help off these boards for these fixes, I'm guessing."
Don't need to guess. I think I posted the how tos from the Ford CDs previously.