We are both nurse and plan to travel for a good portion of this time, so 'living' in the small 1br or studio apartment for residence purposes will not be a major issue for us since we will rarely be there.

HELOCs often have lower interest rates, and the interest may be tax-deductible if used for investment purposes.

Most purposes that people on the BP forums are transferring properties to an LLC, would be exempt of the Due On Sale Clause. 

Purpose of the fund: To purchase old land, rezone, demolish, and rebuild homes to sell at a profit.

That is where the concern would be for me.Yeah, older tenants may think that it automatically makes someone a criminal of something, but I would just explain the card and that it at least, in theory, has a medical purpose, unlike cigarette smoke which kills the smokers and everyone else around.

To me it kind of defeats the purpose of protecting personal assets and standing up the LLC.2. 

You do not need to have it under an LLC to take depreciation, the LLC's purpose is to protect your personal assets should you get sued.  

Our lender has informed us that we need 12 months of rental history to use the actual rent for financing purposes, or we must rely on the appraiser's fair market short term rental value.

That sale should qualify for the $500,000 sale of personal residence exemption for tax purposes.

For bookkeeping purposes, I recommend designating a separate bank account exclusive to the house hack activities to keep some sanity.