After one summer of STRs I came back in the winter took a first lean mortgage on the property to replace the roof (and build my RV which I plan on living in while renting in the summer).

Your mortgage payments may be fixed, but your taxes and utilities will increase, your maintenance material costs and labor rates for repairs have gone up, and your property is wearing out (appliances, flooring, water heaters, furnaces, roof, etc. all have a lifespan and will eventually need replaced). 

What about leaking roofs or accidents you can't predict?

This leaves the tenants extremely frustrated, especially if it's a refrigerator issue causing their food to spoil, or possibly an issue with an appliance leaking water onto the floor, etc. 

To make things even more complicated, I could possibly have roof issues, which means more $$ spent that I won't earn.

The roof was replaced this year and the Central Heat and Air unit was replaced within the last 3 years. 

You just need to shop around more and take care of the big items, like the roof, if needed.

-You'd also want to understand what kind of capex issues you are inheriting....does the roof need done?

Well - sale prices are through the roof right now.

You kill two birds with one stone by giving yourself a roof over your head and an investment property at the same time.