if they just want the membrane out, dry out the existing sub, then put new soundproofing in, then the 5k might be just fine.

Realtors response was it/they were just dry walled when listed, and  Franklin like other places is a bit oversaturated with new construction at the moment and the higher rates are not helping any. 

I'd like to finish it with insulation, electrical, dry wall, treaded stairs, etc. 

Since my home had only a bit of dirty water in the laundry area, supposedly the mitigation company cleaned the area and set up fans for drying.

Odor abatement companies charge that much because they will have a machine and an enclosed system in place to suck the odor and source dry so it will not come back, my opinion is you are stuck with that or finding someone who doesn't mind the odor.

Give them a day one which it is going to be done and tell them the floor needs to be clean and all the furniture removed from it-plus they can't walk on it for a set period of time until the floor is dry-probably a day or two.I'd also make sure you increase their rent because my guess is when it comes to replacing the floor AFTER they move out, you aren't going to recoup what you expect from them. 

Deals are being done every day long after a market has "dried up".

Chad I find these NE states to be quite complex compared to the west coast states that are really cut and dry when it comes to these issues..

(3 by 6-foot hole in dry wall; Garage access door complete broken off with damage door frame, the main entrance door way frame is broken and need to be replace, damage to the rear entrance door frame as well).

Then move forward with a restoration company or trusted contractor who can help you dry out the place starting tomorrow (or ask your existing contractor for recommendations).