There about 100 million posts about “what should I do with X amount of money” so I’d recommend utilizing the search function to find those and read them.

You may want to partner with someone who's familiar with the marketing side of flipping, because this is the most important function.

The "popularity" is just  a function of how many gurus are trying to make money selling you the "secrets".

Unfortunately most detached duplexes are smaller homes (our largest is 4 BR/2 BA but most are 2 BR). 

-What is the smallest/ largest loan you make (to see if you can build a relationship and scale with this person)?

It may be that most of the largest syndicators only take accredited investors but there are many of us who are happy to work with non-accredited investors under rule 506(b). 

There's a function IRR in Excel that does this for you.  

I would plan to pay for majority of upgrades with a line of credit.I have a few additional reasons beyond monthly cash savings to sub-meter the electric: 1) There is one thermostat in the house, controlled only by tenants in the largest unit.

I was already leaning to the side of just stashing the money away so it will serve either/or function, first as a down payment for your next property or money to pay major capital repairs or improvements.

I like the idea of college rentals as you just need them to be functional not nice (since they will get beat up a little each year) and that is what deposits are for.Definitely require a co-signer, normally it is the parent of the kid.