The buyers entered the property (without permission) and made major modifications to the house(before closing) ie. taking down walls, doors, stealing tools from the garage.

So they went ahead and made modifications to your property without permission?

As for the elaboration, I went through some financial struggles in my career (fossil fuel) a few years back and was forced to do a mortgage modification.

On a side note, did you ask for proof that electrical modifications were done by a licensed electrician? 

I was recently fined summons that a 4 family unit that was built in 1952 with 2 electrical meters must have 5 meters for each floor including a landlord's meter, 2 additional boilers, 2 water heaters etc...The strange thing is the home has been in the same condition since it was built, no modifications and the utilities have been in our the landlord's name for over 10 years. 

The walls have been cut to widen and other modifications made to accommodate.

Additionally, even if that obstacle is overcome, say the lender requires a lender required repair.....the deal will not close as HUD forbids any modification to the property prior to closing

If they need modifications they are to pay for them (and pay to have them undone when they move out).Once the work is done and they are happy they will be more "sticky," less likely to move out.

They have latest / most current loan docs (especially if there was a modification)

@Nathan ClaireThanks for the substance and silliness ;-)A modification/addition to the BRRR method I’m considering are ADU’s/Accessory Dwelling Units.