I'm sorry to hear about the loss. I do think it was best for the dog as it seems he does not like mankind. Good luck with the new pup, actually when I was looking into getting a dog I was hoping for a schipperke! I bet she's wayyy cute. Remember, patience is key! I think it's odd though, that your mom bought the dog and just left it with you as it is her purchase, and a puppy requires a LOT of attention and care! Weird. Well anyway, I hope it all goes well--
One thing I forgot to add -- (this is not a slaponthehand just a serious concern!) Please, never ever ever ever EVER hit an animal again. I'm sure this has affected Capone maybe even more deeply than what your neighbor did and probably even confused him. -In that, he loves you -- and you physically hurt him. Beings learn from those who they love most.
I am sure you understand already that is inappropriate behaviour, however, many people are just prone to repeat subconsious behaviour. It's hard to ration when you're stressed and frusterated, I know this above many things!
Just, take care, and love any animals that you associate with. Remember you are shaping their little impressionable hearts and minds in everything you do.
I hope all goes well for you concerning your personal health and well being. I'm not giving you pity or anything like that, like i mentioned above, I can relate to the social stuff. : ) Take care.