RE: Neighbors not feeding their cat, may be moving.
That is so sad. I almost ended up with a cat due to similar circumstances. A neighbor had moved out and abandoned their cat, a sweet calico mix that was talkative, but just loved anyone who would love her and wanted to hang out on my lap all the time. I ended up taking care of her for a little while, but I was doing it under the radar basically because the property management company said no pets in any of their apartments, so obviously this cat had been kept illegally in the first place. I only let her in when I was home, then one day she didn't show up again. I am hoping in her roamings while I was not home she found someone who was able to take her in and be a better person for her than I was able to be. I would have loved to have her, but her personality and my schedule weren't exactly a great fit. She would have been perfect for a retired person.
I hope things work out for this cat, whether that's with you or the neighbors. This cat seems to be an outdoor cat, or is accustomed to spending quite a bit of time outdoors, so that's a good things for you if you become the new owner as the cat will likely enjoy being on its own for many hours of the day, not demanding large amounts of attention from you. Good for you to see that the cay eats right now while the neighbors aren't paying attention.