Your questions are not tax questions and, actually, are not even legal questions.
Regardless, you are simply not going to be able to circumvent Fannie Mae's limit on 10 financed properties (obviously, this refers to investment properties). If the lender is going to sell the mortgage, the limit is going to come into play.
The best you can do is try to find a lender that will write a blanket mortgage or that will retain the loan(s) in its own portfolio.