There are a lot of fundamental problems with the way these places are managed, and how they treat their tenants.

But the thing is that would you tell a rookie just to go into real estate without education blindfolded or should the rookie learn the fundamentals of REI before jumping into the game?

On my fundamental level of understanding, one roof for two units means two sources of income covering the loans, and all other expenses.

You don't need to get the license, just get the fundamental education.

The difference between the average daily balance of the HELOC by depositing ALL your income into it - and using it as a checking account is what does the trick.The fundamental mathematical principle is not "paying extra on principal" it is REDUCING ACCRUED INTEREST - which results in more money going toward principal. 

Keep it in mind, as you can self manage it (practically) forever but that time is money, and you should account for that - nobody wants to work for free.At the end of the day if you’re confident in the fundamental numbers of what this asset will return, then you’ll be fine.

It's like asking a pro athlete how they do something, the answer rarely goes beyond fundamentals and clichés. 

The investing fundamentals always seem to circle back to location and supply/demand.

So the fundamentals are key.  

The fundamentals of limited liability depend on more factors than just a different name.