So I'm basically screwed until they get the site back online.

Don't feel like you are the lucky one to have a cash buyer calling you, and don't screw it up and waste your time and effort by asking what are you looking for.

They screwed up.

If you make a 25K for example and the contractor screws up and another 5K is required, you can advance that amount and it will be secured.

I would never rent to someone that did a short sale and screwed the lender they would be nothing but problems.Joe Gore

The grade A companies had thousands on their email list but more importantly a good group of high volume investors that don't screw around and will grab properties from under you at the retail+ price.

You net the two amounts out and either add the small gain to your income side or the small loss to the debt side.As long as your property has reasonable cash flow (400 to 450/mo), you should be getting a small bump to the positive in your DTI for each rental property you own..As long as your properties cash flow reasonably well, the rentals should actually improve your DTI ratio for qualifying for the loans. (1) You are correct, REI calculations are those most commonly screwed up by lenders.

Since I have zero experience, I want to make sure I have some extra cushion in the deal for what I screw up and/or miss completely - and I just don't think that's going to happen with how hot the whole market is.

Put the key in a lock box in a area of the house he can access, inside, not hanging on a outside door.. or maybe just inside of a door frame , (some can be boxes can be screwed on frame so it's not hanging).what's also important is communication that your having the unit serviced and letting tenant know the maintenance guy is expected..For emergency service this is just plain awesome.. and you can always change the code if you feel it necessary. 

Dont screw with that)  If things look pretty good with the above (doesn't necessarily have to be perfect), move to step 3, pull a permit for the suite (only, for now).