I agree with many of the things that Tim and Jessie have had to say.
Cats are wonderful pets, but they are definatly not low maintainace, especially a kitten. A kitten will get into anything and everything, even more so if it doesn't get enough play time. For your situation, as a first time cat owner and since you may not be able to be around all the time, I highly reccommend getting a cat that is 2 years or older. An older cat will still have plenty of spunk, but won't require quite as much attention as a kitten. Actually, if you plan on not being around as often, two cats (that get along well) may be better than one. That way, when you're not around, they will have each other to keep themselves active and entertained.
A lot of the answers to your questions will depend on the individual personality of the cat.
A scratching post is a must. I hear the best scratching posts are usually made of sisel rope and are tall enough that the cat stretch out completely. If you're somewhat handy, one of these can be very easy to make. Having a scratching post, though, may not keep the cat from scratching on furniture. It will take patience and dilligence on your part to teach the cat appropriate places to scratch. Declawing a cat for this reason, IMO, is unacceptable. I, as well as many other people, do not believe in the practice of declawing. It is known to cause behavioral and psychological problems for many cats, and is very painful. I suggest reading THIS POST
to hear what others have to say about the practice of declawing.
Our cats don't chew on things like fabrics or cords, but the will chew and try to eat other thing like string, rubber bands, houseplants or other small objects if they get the chance. These types of things should be kept well out of reach because serious problems can result if they eat them.
We have two neutered male cats. When they started to reach maturity, they did start to spray, but this stopped as soon as they were neutered. Female cats, if unspayed, will go into heat every month or so. They will call constantly, their behavior will change, and it is extremely annoying.
I would never leave my cats completely alone for even over a day. Too many things could go wrong. What if the cat were to get sick or hurt itself? By the time you returned, it may be too late for help. If you have to be gone on occasion, it is best to get a reliable trustworthy person to check in on them at least once a day. A cat needs fresh food and water every day, and will get bored if let alone for too long. If you are gone for long periods of time often, then getting a cat is probably not the best choice.
We cannot leave food out unattended, especially bread. If I were to leave a loaf of bread on the counter and leave the room for even a few minutes, the cats would tear the bag open and eat it. Bread seems to be one of their favorites, and I have no idea why.
Cats and rabbits can get along. I have 4 cats and a rabbit and they tolerate each other just fine. My rabbit is a large breed though, and I'm not sure if I'd trust the cats with a dwarf rabbit. It isn't even neccessary that the cat be young when introduced to the rabbits. All of our cats were ex-strays, so they have strong hunting instincts, and they were all introduced to the rabbits as adults.
There is a TON of information on this forum. You can do a specific search or just browse around, and I'm sure you'll find lots of information that will help you decide if a cat is the right pet for you.