It all comes down to being able to effectively mange the property and attract stable tenants.

I may consider hiring a management firm and pay them so much a month to mange.  

I have manged people and personality's always from manager to supervisor to owner in all my jobs, so I feel I should be pretty good at the landlord aspect of it.

Do you have a network of people to mange the project day-to-day?

Should I hire a property management company to mange my 3 fam if I am living in it?

He would like me to mange the flips as well as find the deals etc.- My question is does the investor have to be a residence of the U.S. in order to purchase?

Since I don't have the time right now to mange myself, it seems reasonable. 

It's a lot more labor intensive and requires more capital upfront to buy supplies and mange turnover. 

However not near the drama  his job is to mange the onsite managers..

If you mange to buy 1 good deal a year you are doing well. but of course you can do better if you put more time in to it.The LLC would come in to the play at the stage when you close on the deal, OR after you took ownership. some lenders (conventional 2-4 mainly) would allow LLC ownership. -- seek legal advise.