I understand this isn’t a huge deal, but in all that I’ve done I’ve avoided issues like this. 

They deals he says to go after are the ones the real experts say to avoid.

Your idea on the social work aspect is right on.

Looking for permanent structure over being on wheels to avoid RV parking issues with the city and for the property value add with the permanent structure.

I personally would avoid the older neighborhoods closer to the post.

I've never heard the 25% thing before, but any difference between FMV and sales price would technically be considered a "gift" with potential tax implications for your parents.You can avoid most seller costs as there's no reason to use agents in this case.As an FYI: I always recommend avoiding a FHA loan, if you qualify for a low-down payment conventional loan.

Mainly I’m trying to avoid “aged poorly design” glassblock walls, small bedrooms, older windows (wood/aluminum, single pane), aluminum patio covers, and to a lesser extent landscaping.

Once the lease is signed, I go to the bank and open a new security deposit account, and then the bank provides account number, which I then manually enter in the lease and have the tenant sign the lease again.Any guidance on avoiding the hassel of having to sing the lease twice lease?

Savvy visitors to Mexico avoid certain areas and taking part in certain activities, like they would actually do anywhere."

As mentioned by others, you cannot personally guaranty the loan and the limited recourse aspect navigates that requirement.