Personally prefer SFR..Not sure about DFW but do have a realtor reference for you..be sure to budget for furniture and furnishings if not sold turn-key..a seller concession is a great way to preserve capital for MTR or STR's..check in with @Joseph Chiofalo for an investor friendly lender..he's excellent at helping structure loan programs for investments.

Second because they can’t borrow the amount over the property’s appraised value, even for the furniture.

Please don't destroy the house on your way out, sure... try to take your furniture with you... but broom swept?

They complained of the oven and crumbs under a heavy sleeper sofa they moved when the moved in some of their furniture.

That's how you get the best of both worlds.I will defer to your judgement / answers as you are going to be more of an expert in the area and I am just basing it on spending a few months there and potentially wanting to live there in the future.Maybe I chose a wrong word when I said 'poor'.I stayed in Madrid during my time and I just based my response based on discussions I had with locals and 'high level research' on the internetIt appears that unemployment rate is high in Spain at around 11 percent with a higher rate for those who are younger.A had discussions with many where they are mentioning to go outside of Spain if they want to further their career or get a higher salary.locals have told me that it is difficult to start a business in Spain from getting approval and the taxes are higher for those that are self-employed.My personal assessment, which I think agrees with yours, it will be hard to make a rental work if you target it to locals but if you target it to outsiders, you can make it work.During my stay in Madrid - I stayed in Chamberi, Lavapies, La Latina, Malasana and spend around $60 to $120 a night mostly in airbnb's(basic rooms with basic furniture). 

I suspected that 1st floor condos don't get too much love, but since this condo doesn't have an elevator, I figured it would be easier to move furniture into.  

A lot of people have problems seeing how the space would look with furniture or even what some rooms are. 

Says this is according to Fannie Mae requirements.I explored seller financing but she wanted prime +1% and full asking price and was not able to convey existing furniture to me... so it was less attractive to me.We'll see if it sits on the market, and comes down in price and I can then make another offer.Thanks again!

Apparently, that unit is being treated for the issue and involves her leaving her belongings (bed, furniture) within the unit to be treated.  

One of my problems is that when I rent it the people move there furniture and stuff in and the property ends up looking worse because of the furniture and clutter.