As long as they trust you to make good on the agreement you promised them then you won't have any issue with taking possession of their property and making it part of your rental portfolio.

Sounds right, as long as the loan is used for rental activity, there is no issue claiming interest.

As long as both of you are including insurance + taxes in your calculation, it shouldn't matter whether you escrow or not.Double check with your county on the property taxes, and ask your current insurance agent for a more accurate estimate on the insurance.In your area, is the landlord responsible for paying trash?

So I decided to hold on to my properties and just refi as long as I can.

As others have mentioned, as long as the demand is strong (which it seems like it is), I wouldn't hesitate.

I wouldn't hold ill will as long as my new heating system was working good.

If you're refinancing a rental, then as long as you remain cash flow positive, you're not the one paying it off...your tenant is. 

Their value is more on the legal, asset protection side and so long as you have your assets inside the LLC you should be covered.

However, I have recently found out that you can 1031 tax exchange into a multi-family property from a single family property as long as it is 4 doors or less. 

I find as long as I approach the relationship carefully, most pros in RE are open to helping.