However most who live here are US citizens and have been for generations, although there are a number with Mexican citizenship and legal residency in the US.

I have done some zoning research and it is a big hassle especially with them being out of state (looking to move back home) to try and jump through all the legal hoops to do this. 

The legitimacy of the contract probably only really matters if you have to go to court/arbitration to enforce it.That said, your title company would be a good place to start in terms of getting a legal review, I'm sure they have a real estate lawyer(s) on staff or retainer depending on the state.

Yes, 100% you are allowed 90 days for occupancy and the lender can also grant additional days based on legal issues so long as they know and are made aware. 

That bubble will burst in a very legally challenging way for people who follow that bad advice.Second, you have to be in a position to handle a Due on Salecall.Third you have to be in a position to make every payment on time even if the property is sitting there vacant.You have to know why you are buying the property and what you are going to do with it to be cash positive without question.There are other things but that is a start.

Common complaints I hear is timeliness of communication, but it doesn't seem to be from everyone.

Disclaimer: Not a tax or legal professional. 

Its pretty outrageous if this contract is legal. 

I would go to your states and the state where the company is located, website and file a complaint.

Is this legal of me to still require the ESA dog to be fixed?