Cat bite abscesses are a serious matter for you and Scruffy. I think any future bites should be followed up right away with a round of antibiotics. If you haven't tried it yet, soaking in hot epsom
salts will help with the swelling and pull out the infection. You might need to see an hand doctor if one of the punctures hit something important like a tendon in there.
Around here, they are supposed to report animal bites to the health department. If Scruffy gets too many reports, he could get in trouble. I would make sure his rabies is always current.
I don't know if Scruffy will mellow out with time, but can you try feeding him at the same time, but before serving Free Loader? It might distract Scruffy and also teach him to associate the stray with snacks. Were you able to find a TNR clinic in your area? It would help some if Free Loader could get fixed and vax'ed sooner than later. If there are fewer hormones around, it could help with the aggression, and will make Free Loader less "smelly." Will Free Loader let you touch him yet?
Neighborhood Cats | How to TNR | Feral Cat Winter Shelter Neighborhood cats has a lot of information on TNR and helping feral cats. My feral Mama's have been doing well with their Rubbermaid shelters for the past 8 years. I used a sheet of the Mylar Styrofoam panels for insulating the Rubbermaid tote, and lined everything with straw. One sheet is the right size for a single-cat tote. Their fort (houses) are covered with a tarp and placed under a bush in my back yard. The houses are on a thick layer of straw since I spread the balance of the bale under the tarp after lining their totes. It keeps everything above any snow melt and ice during the winter.
I use a heated birdbath in the winter to provide water. It sits on an overturned plastic litter box to keep it above the snow. The bird bath was from Wild Birds unlimited, and I picked it because it was designed to be out in the elements rather than inside a sheltered area like a heated dog bowl.
