If so, any law firm or agency you can recommend to help with this?

You can't hold them accountable to the terms if they aren't on the lease.I would remove all of them from the rental and start fresh.

My primary concern with two separate leases is that it would be extremely challenging for you to remove a tenant via eviction for any reason because technically it is one unit.My recommendation is to provide one master leases signed by both groups of occupants.

If they are truly a local firm you'll want to vet their experience thoroughly to verify that they have the depth of experience to handle what you're anticipating.

Does providing complementally k-cups/teas, popcorn, spices, toiletry essentials (toothbrushes, floss, bath wash, shampoo, conditioner, soap, paper products, makeup remover, laundry detergent, firewood with firestarters for the fireplace and firepit constitute as substantial services?

That synergizes well with snow removal and lawn care seasonally.

I used Mark's firm a couple of years ago on 4 tax lien foreclosures.

While this may be a clear lease violation, there is no guarantee that the judge will grant the removal order and give you back possession of the home.You need to weigh the costs.  

I wonder how pissed the spirit would get if you went there and removed the doors so he couldn't slam them?

It is 100% a great program to get into and I love everyone's different views but I have also signed 2 new section 8 tenants since I posted this so I am staying firm in my belief!