This is a house-hacking strategy that many individuals are utilizing to cover their mortgages right now.

This is typically the method for on-market/MLS properties, as I'm sure you know, but you could also offer a commission to your agent if they help you with an off-market property.

What I just described is typical for A or B grade for me in Baltimore. 

It’s two brick quadplexes side by side with separate utilities.

I don't see that it would add appreciable value for the appraisal or for rent, AND when you go to re-sell you would probably want to tear all that work out and put it back how it is now as your typical buyer is probably an owner-occupant and would prefer it as it is now.

Between the four 1b/1b units, the property generates $3,800 in total rent, and all utilities are paid for by tenants.

Some things you may want to consider:  does the rent on these units include utilities?

I partner with people a lot but typically they are in a more passive role. 

You are going to want to utilize what is called a DSCR loan.

There is absolutely nothing illegal, unethical, or immoral about utilizing a subject to strategy.