I'm basically stuck with a pair of commercial units where anyone who could object to my possession is dead, and it's the lack of heirs that secures my position.

You are absolutely correct that we are focused on long-term ownership, as long as the home is appropriate for you, as part of our objective of community stabilization. 

The objective of my post is to get advice from experienced professionals because that's what newbies should do.

I’m new just like you and similar objective - to build a 10-20K sqft office building. 

Lender wants to change that which I don't so much as object to as that he is saying no professional lender does it like we've been doing. 

The objective is to start building your team and also ensuring yourself that the deals you're looking for can be found in the market. https://www.biggerpockets.com/blogs/10145/70795-ho...3.

"The commercial real estate is business-focused real estate which involves property that is sold, leased or used to achieve a predetermined business objective.

That could be good or bad depending on your investment objectives. 

My objective is to build a portfolio of 5-10 exceptionally managed rental homes and stabilize the portfolio within 18 months of initial acquisition. 

no, i think its the opposite... you get objective data by putting in the numbers on the spot (roof cost, tile, new toilet, kitchen), punch those in, hit a button and get the number right there.often times i can't remember if house x needed new pipes or not after i get home.