I would be straight up and say "I really appreciate the mentorship and guidance along the way but I am now at the point where I would like to take my business to the next level and I wanted to see if you would be interested in a joint venture." 

Sort of why I was hoping to build my network out here to get some leads going and help one another by sharing info or a joint deal.

I would start by asking the seller (or agent), "Are you (or your client) willing to entertain a joint venture?" 

The deduction for mortgage interest in this case would indeed be $33,750.Regarding your second question about the origination years of the mortgages, the limitation on mortgage interest deductions generally applies to new loans taken out after December 15, 2017, for both single filers and married couples filing jointly.

I've got a few mill in rental properties that I've BRRRR'd here in a Oregon, but most of acquisitions have been creative deal structure or joint ventures when we need to raise capital to get to a 50% LTV for maximized cash flow.

This strategic move paid off handsomely as we were able to command higher rents than initially projected.Here are the key financial details of the deal:Purchase Price: $270,000 (jointly with a partner)Financing: Obtained a commercial bank loan with a 30% down payment, 7% interest rate, and a 20-year amortization period.Initial Rents: $1050 and $1250Current Rents: $1400 and pre-leasing for $1500 (making it a 1% rule deal!)

If you've lived in that house 2/5 years as your primary residence, you can also sell it tax free up to $250k single/$500k married-filing-jointly. 

Also you can still get the 250k limit even if you don't qualify for the full 500k married filing jointly.

Kind of, we dissolve the partnership (or maybe not, just the joint ownership of two houses), but we each keep a house, without selling taxes?

I truly do feel like my efforts to get to this position of being able to purchase in the first place would be significantly undermined if I went ahead and split the home through a jointly owned LLC.