2004 GMC Envoy ROOF REPLACEMENT !

In my opinion, a vehicle after any body repair SHOULD be as equally safe as it was pre-loss. This all depends on the quality of your repair facility. They are held to service standards, and should posess the credentials to prove it. I-Car certification, ASE, as well as any factory certifications should be part of the resume. I don't know which state you are in, and what specific laws regarding insurance repairs are, but you should have the right to chose your facility, and not let the insurance company do it for you.

One would think that such a repair on a 2004 vehicle at 140k would total the vehicle. Often times if the repair is a certain percentage of what the vehicles blue book value is, it is a total. I want to say 75%, but don't quote me on that. Then again, it may differ, state to state. If you have had the insurance appraisal, and they have suggested a shop that will work with their estimate, it could just be to get the work in the door. Obviously, it looks a bit undriveable, but you have the obligation of having a shop of your choice do the estimate, and repairs. Hope that answers some, if not all, of your questions.

You should have mentioned that the repairs were in progress/near completion in your original post. There is not much that can be done for a second estimate, since it is not in damaged state, and you probably already signed something or otherwise authorized repairs. The salvage title would only occur if the vehicle was totaled, the insurance company settled the claim, and the vehicle was repurchased and reconstructed. Resale value, it is hard to say. There may be some hit to the resale, but once a vehicle crests 100k miles, it goes down substantiay from there. I would imagine that it(accident) is going to appear on a carfax report if checked. You sell it private party, and that info does not necessarily need to be disclosed, unless someone checks the carfax, or there is suspicion.