Some cats, if separated from moms up to 2 weeks of age, can develop biting behavior (they never learned that being bitten hurts). Your kitty's problem is far more likely to be a result of the declaw that the owners who dumped her performed.
If you can afford it, I would definitely recommend the Feliway plug-ins for all large rooms in your home that she's in. Or just go for the rooms she spends the most time in. This will help provide a "calm" environment in which to do everything else.
I would also recommend the Flower Essences. It can't hurt, and it does sometimes help:http://www.petsynergy.com/flower.htmlhttp://www.catfaeries.com/essences.html
Biting (unfortunately) is natural for declawed cats, however, this activity needs to be redirected, and biting people needs to very clearly be defined as an unacceptable activity:
1) When she bites a person,
a) If she's got a hold of a hand or wrist, push it IN to release the grip, do not pull.
b) The whole family needs to be instructed to blow a short, sharp puff of air in her face and then even hiss at her. Say "NO" firmly - do not shout. Then walk away and ignore her. She needs to learn that biting will NOT get her attention - in fact, the opposite happens.
c) Someone on this site had a cat that would NOT stop biting. When the cat bit her, she leaned down and bit the cat. This stopped the behavior. I'm not recommending this, but giving you something to consider.
d) If the puff of air and the face and the hiss with a firm "NO" then walking away and ignoring her don't work, start using "time-outs." Pick her up, put her in the bathroom, and leave her there for five mintues, no more. Apart from learning that the biting people doesn't get her attention, it gets her isolation. But it also gives her "hunter-prey" attack mode time to turn off.
2) For biting the couch or other furniture. Just like with scratching, as I wrote above, this needs to be redirected. Her natural instinct is to scratch - but not having claws, she needs to bite:
a) Purchase apple bitters or cream, test a patch, and if it doesn't harm the leather, put it on the couch.
b) Consider using throw blankets to cover the couch for a month or two while you focus on getting her to bite on appropriate things. Try a number of things to see what works. Get rawhide chews. A chamois cloth. Bendy straws. Nothing rubber or hard plastic that could harm her if pieces come off.
c) If she's biting at the bottom or back of the couch, consider covering it with aluminum foil for a month or two. Again, this forces her to redirect the behavior and after that amount of time the "habit" of using the couch as her biting post (so to speak) will have been redirected elsewhere.
You may not know: cats actually walk on their toes. So when they are declawed, they have to change the way they walk. For some, this distorts their natural movement, and it is actually painful. Others are fine - but they do have a tendency to develop arthritis. She's probably too young to have arthritis (unless she already has a genetic predisposition for it). But just keep this in mind, get her checked regularly, and at some point in her life you'll probably want to introduce Cosequin (basically glucosamine for cats). This will help prevent the development or progression of the arthritis.
OK. I read through lotsocats thread (this one: http://www.thecatsite.com/forums/sho...hreadid=20837)
Apart from the info I've included, I'd read through that thread - especially scrolling down to this part: "For the Rare Cat Whose Attacks are Unprovoked and Extremely Violent."
As to the other nutty behaviors? I would have her checked to make sure it isn't a thyroid problem. Double-check the arthritis, even though she's so young.
Also, as she seems to have a lot of energy, one of the things that might help the most is to have everyone in the home spend 10 minutes of their day playing with her. Interactive wand toys would be best - something she's got to chase down, run around, leap around - use that energy, but direct it into activities that don't harm your furniture or walls.
Do you have any cat furniture? If not, consider purchasing a cat tree or two. A combo of carpet and sisal would be appropriate - gives your other cats something to scratch on too. And then she's got her own "furniture." If you've already got cat trees, try purchasing some catnip spray and giving a good squirt or two to one or two places on the tree to help attract the kitties to it. Bear in mind that cats develop "immunity" to catnip, so do this only once every few weeks. And if you have catnip toys, don't leave them out. Pick them up, put them away, and only put them out for a day at a time every few weeks, or they become insensitive to it.
Hope some of these ideas help.