I’ve heard that a debt settlement attorney can help negotiate with creditors to reduce the total amount owed, which sounds appealing, but I'm a bit unsure if the cost is worth it, especially since some charge high fees.Has anyone here worked with a debt settlement attorney?

Without a hours-long conversation, here are things I consider.1) I have never invested with anyone that charges an acquisition fee, and most syndicators charge an acquisition fee. 

They charge 1/3 to 1/2 of the amount of money they save you.  

You get charged retail .

We use a guy form Upwork who charges $.25 a search with no minimum.

Also check for complaints against the lender.Also get a detailed statement from the lender of all closing costs, fees, charges, etc., etc., well before closing.

fair return methodology used must be “concerned with the financial integrity of the businessas a whole, not the ability to obtain a return on a discrete portion of the business.”MNOI presumes that the rents Landlords chose to charge, in a year free fromthe idea of rent control, provided Landlords a fair return on their investment,as the rents that were charged were based on general market conditions, andnot the upward pressure that policy discussions of rent control may have onthe market.

And you can tailor it to you, so 1) You certainly don't have to charge 100% while vacant (dependent on bldg. layout, thermostat access, etc.) and 2) You can tailor the Gas/Electric as you have brought up so maybe 50/50 all except 60 unit 1/40 unit 2 for electricity... etc. 

I have an opportunity to raise capital with a private individual at a flat interest-only rate as a way to reduce interest charges and eliminate origination and service fees.

You can charge pet rent, a pet deposit, or both.