For example if  grandparents are traveling with their kids and grandkids and they need some downtime, if you have a whole separate structure on the property, they can go recuperate for a few hours by themselves and then join the rest of the family later on.

Any bank will have you file paperwork for recuperating the money and they will be given a copy of it.  

I thought if I had a rough or exact amount the bank needed to recuperate, I might be able to get a deal.

I recommend finding out exactly what those penalties will be and making sure you will recuperate them in a reasonable amount of time.

Also, I think there will be more chances to fail and more time to recuperate if the money you put away for your first REI didn't come out as expected, specially with recurring debts, for a first investment. 

Owners are going to want to recuperate all the lost capital.