Also, check to see if your jurisdiction is practicing "Just Cause Eviction", which went into effect statewide earlier this year for municipalities that which to opt in. 

We did a master suite addition to the property What was the outcome?

They're often high quality and cost-effective.

I never had that come into effect on my single family home purchases since I never wanted to personally be on the hook for such a high mortgage, but I think it might come into play for an MFH. 

I ended up investing out of state in a more landlord friendly / cost effective market.First thing I'd recommend is figuring out your investing strategy (single family / small multi-family 2-4 units) and attend some local meet ups to network with other investors to learn from their mistakes.

If you didn't pick a tool that quite obviously works because of a factor completely unrelated to the effectiveness of the product, my course can't help you, ..

He felt spending more time disputing the rejection was not cost effective and i see his point but suspect airbnb recognizes this and uses it to their advantage.  

I am a strong advocate for their effectiveness allowing you to do substantially more with your money. 

Yep for one especially in the early stages a hard credit pull would not be useful, just have them do soft checks for the time being and opt out of credit solicitation: www.optoutprescreen.com I could be biased... that said typically working with one lender than can help regardless of where you're looking and having a relationship with that will provide the easiest and most cost effective route long term. 

Plus for its high cash flow potential, utilizing a 1031 exchange to reinvest gains effectively made this experiment a relatively low risk for me.