[Hoof Hearted]

I foster cats/kittens for an adoption place and I also tame and socialize feral cats. Almost all of our cats were ferals that showed up on our property and I tamed. Once I spent money on them getting them spayed or neutered, they became "mine". They've all become great housecats...but you are right: if we don't give them consistent attention/handling, they will drop off the radar and revert back to feral pretty quickly.
I stay at home, no kids, so the cats probably get too much attention, but they are all happy and confident around us.

I also think you may have something with the neurotic/inbred diagnosis. One of my friends had a super-skittish cat that just would not settle down into the household routine, though the other cat flourished and did great. Sometimes, I think, some cats are just 'weird' and that is how they will be. She is lucky she has you to be patient and work with her.
hh