Based on what you're describing, I would assume you have an empire or real estate holdings with significant liability issues, and you already have significant insurance coverage.

I am thinking this won’t help my debt service coverage.

I have contacted several insurance agents for quotes/coverage strategies and recieved conflicted information.

Check on insurance coverage for owner damage to the units.

You'll also need some kind of 24-hour coverage for emergency maintenance, legal and accounting support, and compliance (in most states, you have to be real estate broker - which makes you subject to State audits of your escrow accounts, etc -  to manage for other people).If you prefer to focus instead on building your real estate portfolio, or other things, then you'll eventually need to hire a third party property management company; You may be able to self manage 15 doors but what happens when you get to 50, 75, 100 doors? 

Also look up rules on each zone for lot coverage and FAR (Floor Area Ratio) as this will be able to tell how large you can build. 

I'm about to embark in a fairly comprehensive rehab of a multi-family property (electrical,bathroom, kitchen, sheetrock, and various other improvements.

I routinely work with numerous organizations that have a 1000 or more corporate vehicles including LLCs where sequestration of liability makes perfect sense given the relative active business risks which are enormous and the relative costs of establishing and maintaining the structure are negligible.So again I say show me a small real estate operator that has been saved by an expensive and cumbersome legal entity structure that couldn't have been done it at least as effectively and much more efficiently through fundamental risk mitigation practices which disciplines one to act responsibly from the outset.In other words, running what are essentially passive real estate activities by retaining competent and professional management and a modest amount of insurance coverage (which should effectively limit risk sourced to the RE activity), and if you need additional coverage (for risk sourced outside the RE) get some ultra affordable umbrella coverage.Now I realize you won't be able to able to strut down the street pretending you are a player because you have an LLC, but it seems to be a very very small price to pay for not being played for a fool wearing the LLC trappings of a clown.

DIY can end up not full coverage when they paint it back or end up paint on the floor/ceiling and I personally didn’t want to deal with that.

Another section the financial covenants, has a debt service coverage ratio defined.