The back side shows you the screw holes attached to the trusses.

I have been down this rabbit hole and just want to convey to you my own experience. 

A Bank is effectively the current owner, and even if in your optimistic universe they were to contemplate accepting circa $100k rather than their owed $290k (LOL), such contemplation is likely to take a lot longer than you'd be counting on, meaning that the Contract you would have with the naughty "owner" (whose only aim is to get money out of you), will start burning a hole in your pocket.ie. 

I would help them and yourself by ending it before they get too much more in the hole, assuming that they are going to be paying back the other 20% rent that they haven't been paying.

If it is a total sty you may want to be careful, but if the plumbing and electrical work and there isn't a gaping hole in the side, save yourself 10k and live there. 

You have to find a goal bigger than a monetary value to propel you forward.

There are holes in the shingles at the peak of the roof that you can stick a finger through.

I cut a hole to identify the source and it looks like it was coming from the HVAC (currently set to heat). 

Welcome Matheus,Grab your favorite energy beverage, get comfortable, and get ready dive into the wonderful rabbit hole of Bigger Pockets.

While you do need it to refund any remaining balance on their security deposit, or an accounting of any deductions if you end up keeping the entire thing, the real reason you need it is because there could be monetary damages and additional rent they're liable for (since they're breaking the lease).