Any taxes not owed, a seller merely file a tax return with the state, just like any other tax returns filed for extra taxes a government has with held. 

If you’re comfortable with a bigger investment, a duplex is good for the benefit of additional cash flow and you could house-hack.

Part of considering acquiring a property should include additional possibilities.

I should have ran the plumbing for it even if I didn't plan to add it.  

I've seen some people house hack a single family home by renting out the rooms, but keep in mind that traditional lenders would not be able to use the income from renting out the rooms (known as boarder income) towards additional income on the application.

When evaluating a property management company, it's important to look beyond just the management fee and consider the full scope of services and costs involved.For example, at our company, we charge a 10% monthly management fee, a $250 lease renewal fee (unless it’s a takeover tenant, which requires additional effort to establish a strong relationship - because usually people are changing pm companies for a reason), and the first month’s rent as a leasing fee.

Also, check state-specific tax laws, as some states impose additional transfer taxes.This post does not create a CPA-Client relationship.

For this I’ve taken the payment amount of the second loan and included it as an additional monthly expense.

Part of that is adding additional cost for increase in building products. 

Usually, a single-member LLC to avoid filing separate tax returns.