We are weighing whether to apply some of our bloated opportunity fund against a couple rentals @6.5% (commercial seller-financed from 2005) or our primary @3.4%, and have found the following 2 main arguments against paying things off. 

Occasionally, the owner would want me to just hire an electrician or plumber, etc., if the job was something he didn't want to deal with or knew how to do.

One has been paying late but she had did that occasionally before coronavirus hit.

The tenant has access to backyard (not in lease but offered as a freebie) it's in decent shape with not trees or plants whatsoever but my neighbor's back yard is lush green and some of his plants creep into the backyard.There will be occasional uninvited guests such as Centepedes and Beatles when the tenant opens his door.Now they are asking me to call in for an exterminator,the previous tenant never once mentioned it to me.Its not an infestation so I think it doesn't require me to call for an exterminator,it's not an infestation per se.How do I handle this demanding tenant?

He offers a lot of good advice and occasionally offers some bad advice.

You have an occasional scratched up door, but they are very happy to pay for that.Rent is on autopay, that eliminates most of the late payments.

And then occasionally you get a big expense like a water heater goes out or furnace.  

I thought the practice was illegal, but from what I can tell it is just that it would be illegal to demand the entire year's rent up front, but ok if they offer it.So far, in my limited experience, it has been the parents of college kids who offer this, and occasionally someone with less than stellar rental history who wants to dangle the carrot of a whole year's rent in front of me to entice me to look past their past.Kelly

I rent the entire space that is included in my rental contract, and have the right to "own" that space as if it was my own property - within reasonable exceptions that I agree to (like occasional inspections or agreeing to not paint the walls a different color or put in a swimming pool, etc.).I know you're trying to get the place in great shape, etc.  

We've shown units before they were ready, and you occasionally then get that tenant who is really picky - they cop an attitude that it's like they are buying a new house when they move in.