While I've typically focused on single-family homes, my journey into real estate began with buying my first house using a VA loan and house hacking it, then acquiring additional properties from there.

Homeowners might have different needs that a single package can't fully meet, and getting everyone to agree on one provider could be a challenge.

Turnkey is smart for what you are saying, but you have to completely authenticate the turnkey provider. $100 cash flow is not worth it a month.

You still need to do inspections etc. and you are just paying an additional fee.

I was trying to back into the purchase price that would meet my requirements to submit an offer; so based on the rent roll provided, I estimated Opex to be 50% of the effective gross income, amounting to NOI being 50% of $112K therefore $56K.

You will want to make sure the Holding Agreement agreement clearly provides that the monies paid is not the required move-in monies, rent, or a deposit and is a fee to hold the property from being rented until August 1. 

Single family would be easy to sell providing its kept in good living condition but isn't nearly as lucrative as an apartment complex.

You would not be able to access additional cash beyond what was borrowed.The other scenario worked similarly, you can't borrow beyond the cash you paid. 

In addition to giving them what I feel are solid comps (not high or low), I also mention what I think the valuation should be.

The reality is the opposite - if it's not in writing then the PMC doesn't have to provide the service or can charge extra for it!