To further complicate it, I went from from a 30yr to a 15yr in the process, so it not just as simple as taking the difference in the old mortgage vs the new one to calculate the costs of the rental property monthly.

You can have more, but things get a little more complicated.

I'm guessing its somewhere between complicated and/or because you've turned your residence into an investment property. 

Next complication that hit me right after I posted...we owe $120k or so on it, I’m swagging (haven’t done the precise math quite yet) $50k or so of depreciation recapture that’ll be taxable.

Im not sure I answered your question or just made it more complicated, but there are a lot of considerations.

It is super complicate to compete with those that can spend big $$$ in marketing.  

It’s a somewhat complicated relationship, but the overall trend is for mortgage rates to track with the Federal Funds Rate.

The savvy business person may realize these additional, and possibly unnecessary costs, are eating away at business profits that could be used to reinvest in the business and buy more properties!

Make sure to sign an affidavit that you're selling a qualified primary residence when selling, otherwise the title company will report it to the IRS and may trigger an unnecessary inquiry.

I know it’s possible, but seems like it could be complicated and I keep running into roadblocks/restrictions.