3) since we will use a local property mgmt firm for marketing / bookings / rent collection, What business is the LLc in and what income and expenses do you report as those of the LLC (vs what do you maintain personally)?

I've applied for a conventional loan: 3 units, owner occupied, NJ, 5% down.I have enough W2 income to cover the loan and additionally, there are two units rented already. 

Purchasing your primary with this money, unless it produces income, will likely cost more at the higher interest rates of today vs what you have as a rate on this property.

Also maybe turning it into a two family home to maximize rental income is an idea.  

I think you may have very well narrowed down my strategy choices down to one of three; the BRRRR method (although this might be too much to start with for a newbie), the live-in flip that you mentioned (probably the most practical as I've been part of many different projects in the construction industry), and a combination of house-hacking/live-in flip (probably the most rewarding with a potential to swap between units as I finish one in order to bring better rental income).

Diversity the way your income is taxed. 

If someone is making millions to tens of millions a year in income WHY are they going to spend 50 hours with a new person that knows nothing in the field for 10k?

Right now the rental income covers most costs and I’m going to be paying 600 a month of my own money. 

House hacking is for sure the best way to get into real estate investing (in my humble opinion)If you combining your incomes puts you where you want to be, I'd do that.

Following is the income for all the unitsRentsNew Rents Expenses Unit 1: 1800 sqft $ 975.00 $ 1600Insurance $ 6,000.00 Unit 2: 1100 sqft $ 900.00 $ 1100Taxes $ 2,728.00 Unit 3:  1100 sqft $ 925.00 $ 1050Sewer Charges $ 4,800.00 Unit 4(Apartment): 700 sqft $ 700.00 $ 850Vacancy $ 4,000.00 Total $ 3,600.00 $ 4,600.00 Repairs $ 2,000.00 Yearly Revenue $ 43,200.00 $ 55,200.00 Total $ 19,528.00 Mortgage Interest Only/m$1,460.00$1,460.00Mortgage Interest Only/y$17,520.00$17,520.00Current Income Projected Income Net Operating In $ 23,672.00 $ 35,672.00 Cap Rate4.30%6.49%Cash Flow With Int Only $ 6,152.00 $ 18,152.00 Cash invested $200,000.00$200,000.00COC3.08%9.08%What are your thoughts on this deal?