But, as it was conveyed to me by this investor, apparently he was left in the dark about the fact that his tenants had stopped paying, and HW wasn't taking immediate action to evict, which is definitely concerning).

How does the Nest thermostat and smoke detector / carbon monoxide detector work in rentals with tenant turnover?

With the money you'd save locally by rolling up your sleeves to manage acquisitions, renovation, and tenants, and not having to hop on a plane to visit your investments, you'd smoke the return you'd get out of state with a turnkey, and with less risk since you'd be in full control of your own destiny.  

Just the other week I had an annual insurance company inspection and they said a new smoke detector code is in effect in my state

So it's like I'm shooting in the dark.  

don't sink  50k into a rental... use it to buy a business that makes you significant money. if you can't leverage or scale  low end rental game is a dark hole.if the property goes up 10% cost of sales are 7% so until it goes up 30 to 50% is the only time you get any true cash in your jeans when you sell.. at least any that is appreciable.

You need someone who knows the local laws and property codes to market and show your property to potential tenants, vet the tenants, collect the deposit money (which in Texas are required to be held in escrow, separate from the rent money), and the rents (including dealing with late pays or no pays), handle repairs and service requests, inspect the property before the tenant moves in, prepare the property for occupancy & ensure all property codes are being met (safety & security including changing locks, installing/testing smoke detectors, etc.), inspect during their stay, and inspect again after they move out to ensure the property was properly cared for and has no damage.

Just a shot in the dark here, what does her financial situation look like?

I'm totally in the dark about it, but after a quick glance at the numbers it looked more realistic in terms of my price range. 

I would have approved a pet with those details but being kept in the dark isn't acceptable.My questions are:- Who gets the pet fee?