ChrisM
Mostly harmless.
I dunno, if selling the car is an option and you want a dual-use car, it seems like selling the current car as-is and then getting another used one that's bone stock would be better. Then you could put the safety gear in that right away and modify it progressively using the extensive knowledge here (or just do what I should have done in the first place and buy the Ford Racing kit) so it's the way you want it from the get-go.