I think you're spot on. 

Some properties may have operating expenses much high, others spot on, others much lower.Any individual property should be fully analyzed and underwritten to give a good idea how thay particular property will perform.

Self property viewing, online application, electronic lease signing and online rent payment.

Very well done and spot on! 

I recently went through the home-buying process and everything was signed electronically.

., you are absolutely spot on and the reason for such surge in finding investors to identify properties for these individuals (mainly beginners) is because they are afraid and need that comfort of having someone that knows what they are doing.

Tough spot. 

If you entertain this, make sure you have significant cash reserves on hand, as a Roth is a great all-around retirement vehicle... once you take the money out, you lose that spot to put it back.  

When that happens I call the appropriate repair person, the repair person goes to unit and fixes whatever it is, and then I electronically pay the repair person.

There are free educational resources on each of those to get you started, but as you get deeper, @Paul Moore's advice to pay for good education is spot on, particularly for the more active strategies.If you want to do those OOS investing strategies you named, pick one market.