We too have a cat that, when she first came to us was like yours. Her name is Psycho. Fortunately, we knew her back story. She had been raised by a single young man who ran off and left her with his brother and sister-in-law. Unfortunately, they were not "cat people" so they just locked her up and ignored her. She developed a lot of bad habits over time including the behavior you spoke of as well as deification on the bed. We took her in to save her from being put down. OldGal (my friend, wife, lover and companion of 30+ years) and I are both animal lovers, probably due to the fact that neither of us were allowed to have pets as children, and with patience she has become a sweet and loving companion most of the time. Admittedly, it took over a year to overcome the abuse she had suffered, but it has been well worth the effort.
Even feral animals are capable of being 'socialized'. When we lived in Kemah, Texas (in those days a sleepy little shrimp port on Galveston Bay) OldGal spent over a month getting a wharf cat (Now if you want to talk about feral(!)...) just to come into our apartment. It than spent about a week cowering under our bed. She was yellow with a perfect white bulls-eye on her left flank, so the dishwashers and busboys used to try and snap her with dish towels which explains why OldGal took pity on her. We named her Target and she too became a sweet and loving pet.
Some of the other animals that we have managed to socialize are a Fox Squirrel named Shadow that loved to push loose change off the counter and sleep on my chest, a Thirteen Striped Ground Squirrel that we called Buckaroo (HINT: Don't let them hibernate! They get mean when they wake up and you have to start all over again.) An Opossum named Radar, they love grapes and will do anything for one, a 13' Boa Constrictor named Sunshine and last, but certainly not least, Red Bird the vicious attack parrot. You can see her (and me) in action here:
When she came to us she was obnoxious. Loud and just trying to change her feed and water from outside the cage was hazardous to your fingers. It took time and love, and she bonded with me alone, attacking anyone who came near me, but she was was definitely improved from when she moved in.
Over the years there have been a lot of abandoned/unwanted pets that we've taken in and with one notable exception we have (re)socialized them and found them good, loving homes. The key is love, kindness and patience.
OldGuy43
Currently in residence: 2 rescue dogs, 1 rescue cat and 10 Red Sex-link hens.