Could you hold a 2, 3 or 4-plex in an LLC, live in one and still sell the entire building as a personal property sale after 24 months (no cap gains tax)?

If the wholesaler is assigning his contract to you, then GENERALLY you are paying for all closing costs and depending on the state you'd be paying for all the property taxes or prorated taxes UNLESS something in the contract stated otherwise (rare).If you're the end buyer and the wholesaler is looking to close GENERALLY they will pay for their closing costs with them as the buyer when they were direct with the seller, and then you'd pay your closing costs when buying it from the wholesaler "same" day.  

Asking $620k Debt service $4,352/m (10% Interest, 30-year amortization, 80% LTV) Taxes ($1033/m), insurance ($833/m), maintenance($1000/m), property management ($2400/m)Total - $9,613 (very rough estimate) Cashflow with 70% occupancy - $2,387/m (Cash flow pro-forma with adjustments $7,000/m+)What am I missing? 

Your friend may be able to claim interest paid on the underlying loan as a business expense.

Jeff,I would suggest another questions/request for info to add to your due-diligence:    "have there been any claims reported to you, submitted to the Insurance carrier, or that you are aware of, during the past 5 years"I would also suggest that you request that they get the "Loss Runs" (report of claims) for the past 5 years from the current owner. 

You warned her about smoking dope, and she responded with a heart, which indicates she agrees with your claim.

You don’t pay any capital gain taxes.  

However, it is an interesting point since although it's not the last month of occupancy it is the "last month" of the current contract - they could claim to just want to re-pay it at the start of the new contract.

i would be purchasing the property with an FHA loan. and im also looking for solid cashflow + long term holding I think house hacking is great way to get started, especially here in SC so you can take advantage of the lower tax rate.

The additional costs for commissions and costs are negligible in the bigger picture and if you are looking at capital gains tax it's a deductible sales expense which more than offsets the additional costs.