I could bring the HUD statements (showing ownership of the US properties), my US incorporation documents, my Canadian incorporation document (the Canadian company that owns my US business), information about the ownership of my house in Canada (to prove I have existing ties to Canada and no intent of relocating to the United States, etc.)I am a little apprehensive of this and i want to make sure that I do everything correctly so I will not have any problems in the future with crossing the US border.

More than likely non of this is a surprise to seller and there is a reason has not been attended to at this piont, mostly that they don't want to use their capital to do these repairs. 

In other words, there is no actual disagreement.SALT is for personal properties (where you live yourself) and non-rental investment properties (vacant land).

Buying a non-performing asset (an asset that generates no income), that I am only going to sleep in that sells for 6, 8 or 10 times the average income in a particular area, is not something I thought was a good "investment" in 2006, nor do I think it is today. 

Charge non refundable pet fee 200-250 a pet.

It's one thing to be interested in real estate but you need to take an actionable step and commit yourself to handle the obstacles that exist on the pathway to success. 

Structural Vs non-load bearing?

The answer might be too tear down the existing structure and the cost to do so versus existing use and structure with a restoration. 

They pay very little property tax as the home was purchased a long time ago and isn't subject to the normal rates.The question is, is there a way for them to keep their current house, pay off / refinance the existing mortgage or get another heloc in a way that would eliminate the need for the windstorm insurance, rent the house out, and get cash out to buy (mortgage) another property?

There may also be non-monetary factors to consider, such as the family members expected rate of appreciation for the property and tax considerations.