To be honest, when you got your kitten it was going through its growing up stages. By traumatising it during those stages you have permanently ingrained certain fears, wants, and behaviours into your cat. However, it would be handy to know exactly what you mean by 'biting and scratching'. From your one example (tail lashing, pupil dilation, attacking arm on couch) it sounds like a cat that never learned people's body parts are not good play toys.
As for never sleeping with you and not purring; every cat has a different personality. Some purr loud, some drool, some lick, some sleep on people, etc.
If Sky has some serious behaviour issues I wouldn't get a new kitten at all. By doing so you are interrupting her normal life and she may develop some worse habits. I would work with the cat you currently have before upsetting her.
As for introducing cats; some cats get along swimmingly, other tolerate each other, and some attack all other cats. You never know until you try. It's highly unlikely Sky will kill the kitten but you MUST follow proper introduction procedures. You cannot toss two cats together and expect things to go well.
As for never sleeping with you and not purring; every cat has a different personality. Some purr loud, some drool, some lick, some sleep on people, etc.
If Sky has some serious behaviour issues I wouldn't get a new kitten at all. By doing so you are interrupting her normal life and she may develop some worse habits. I would work with the cat you currently have before upsetting her.
As for introducing cats; some cats get along swimmingly, other tolerate each other, and some attack all other cats. You never know until you try. It's highly unlikely Sky will kill the kitten but you MUST follow proper introduction procedures. You cannot toss two cats together and expect things to go well.