It is comprised of 3 identical studio apartments with a bathroom and small kitchen in each.

Lets say I have 100 identical single family homes in one neighborhood owned in two LLCs. 20 are 100% owned by one owner.

You can still get identical results you calculate based on the assumption there’s a 30yr mortgage on the property

Can I HELOC the rest or a certain percentage of the equity of the property or an identical loan package.

My sister had her identity stolen and it took 9 months to sort everything out.Anything in collections you will want to get those current. 

If you have two "identical" units, advertised for the same price and you qualify a Section 8 tenant for one and a non-section 8 for the other.

Can we structure 4 identical loans with these friends/acquaintances, agree to a fair interest rate, reasonable payback/cash out terms, etc?  

Yes...and a mask to hide his identity and TRUE intentions.

Rents have been set to the market rate (they were extremely low)Bought the building for 320k, appraisal when I purchased it came back at 350k. 2 identical comps across the street sold for 399k and 425k.

Although the Scope of Work may not be identical from house-to-house, for the most part, the repairs will be fairly similar.