And with much more in commonality with starting and running say a restaurant. 

So if the deal goes right, I get a return in the form of equity on the house, and my rent is also reduced since let's say, as part owner, I would be receiving a portion of the rent (which I would be paying...).

I know some landlord's show up with something for them to sign or fill out that they previously (on purpose) forgot to give them, but you could also just be upfront and say a visit is part of your screening process - you check the condition of the rooms to see how the unit is being taken care of.

While people will share a bathroom in say a 2/1 it is likely a harder sell in a 5/2 and the price you command is less. 

All that said: I don't know the market you are talking about, specifically, but I would say a good quad in a good location will always be in demand.  

Needless to say a lot has happened since I closed my 16 unit a year and a half ago.

Put the same capital in say a good spring branch area and you'll have considerably higher profit % and $ wise.

They say as I have just seen they will loan money.

I guess the hard part becomes understanding the risk in these investments while having decreased information and control (ex: in say a syndication).

I would say a complete home remodel definitely has challenges.