Here is where I am a little confused:Does everyone over the age of 18 needs a background and credit check or should I only focus on the mother?

Your best bet is to call them and say you are receiving some payment for service performed and is sales tax required, without mentioning "real estate commission".

Like the previous posts have mentioned, the amenities play a large role in determining the rent price. 

You did not mention any geographic info and that information will effect your answers. 

I think it certainly could be, but even at the age of 19 I am seeking out ways for potential financial freedom.

I am married to my wife of 14 years and we have two young boys ages 6 and 8.  

As was mentioned before, it sounds like you already have enough capital to start investing in rentals.

I would go line by line through each property to make sure they made the adjustments property (like condition, the garage you mentioned, etc).It's my understanding that the appraisers can only count legal sq footage, bedrooms, baths, etc.

But you may have some flexibility if getting financing for the LLC is an issue as @Travis Sperr mentioned.3.

As Ann mentioned, I hold a quarterly networking event.