You can find examples of a payment ledger online.Use another section for tracking maintenance.

The building has a lot of deferred maintenance, but nothing urgent—things that could be tackled over 1–2 years.

- How much deferred maintenance is there?

But one of the issues I’ve seen is that most tools require tenants/landlords to communicate through in-app messaging to track conversations, submit maintenance requests, etc.

If managing bookings, guest issues, and maintenance coordination fits into your schedule, you’ll maximize your income by keeping that 20-40%.

Since I purchased it, I've had regular turnover and some challenges.

I own regular apartments as well and I've found that I don't spend any more time managing the rooming house than I do with regular apartments. 

Property managers frequently consider smaller properties unproductive, whereas larger properties allow for more efficient operations and the potential to hire an in-house property manager and maintenance team.With just under 20 units on the site, you must be hands-on.

If you treat the renter (resident) well, provide a well-kept home that you service regularly, and stay on top of any maintenance issues, a resident will likely remain in the house for many years. 

Make sure you add on your lease that tenant is responsible for lawn maintenance (cutting and watering) Summer heat in Houston is brutal and your new grass ( and investment) will be dead by fall.