If you can demonstrate a track record of executing on the business plan you set forth, the banks will continue to lend you money and as they become more comfortable with you, your loan originations will out pace your balance sheet.

A seller will likely feel comfortable at a 20%, depending on the sales price.

It's much cooler and comfortable during the summer months than where I live in the northeast.

Your property manager's comfort zone apparently doesn't extend to the larger project you'd like them to take on.

As a first-time landlord, I'd feel comfortable renting this out knowing that it will not need heavy repairs and know the area wellWhy renting will not make sense:1.

Given the numbers and assuming you can comfortably manage the property or hire a property manager, I would lean towards keeping the duplex.

In this case, we're still within what I feel is a comfortable range."

At the end, it's whatever you feel comfortable with. 

I like long walks on the beach, fine dining and travel....woops!

Here’s how you can calculate the income requirement:Monthly Rent: $1,680Income Requirement Calculation:Multiply the monthly rent by 3 to find the minimum monthly income required:1,680×3=5,040Therefore, a tenant should ideally have a monthly income of at least $5,040 to comfortably afford a rent of $1,680 per month in the DFW area.