A good agent will shrink your learning curve and help you avoid potentially very expensive pitfalls.  

Some pre-payment penalties are as long as 5 years which a likely dropping interest rate environment over the next year or two can be very expensive when you cannot refi because the PPP is to much. 

I managed the properties myself to keep the expenses down.

All normal expenses deducted management maintenance landscaping and so on.Does that sound about right?

We have rented to both businesses that have traveling workers and churches that have traveling missionaries.That said, trying to claim the place where you live as a business expense would probably be seen as tax fraud. 

That's super expensive.

However, the prices I've gotten for painting are so expensive!

There's threads daily about the nonsensical things people do to be a "REI" at the expense of their actual stress, daily lives, and families well being.

And let's say median cost of producing a 3br median unit is $340k.   

With median sea level rising even areas with waterways not considered flood plain could flood and if owners do not have flood insurance they could be SOL.Lots of cold belt states areas are overbuilt since net migration they have had populations move away.