A rabbit loose in the house is FAR more damaging than a cat. They have to nibble on things. Like wires.
Absolutely. As long as they have plenty of hay available, they will generally be lenient on the furniture, but if they are left unsupervised, you will eventually find little "love" nips on furniture, including wood and fabric.
Wires are the exception. For some reason rabbits absolutely love wires and will go after them. With their sharp teeth, they can bite through them quite easily, and this can present a hazard to the rabbit if the cord is a plugged in power cord.
If they're going to be allowed to run completely free, the house has to be rabbit-proofed top to bottom, and damage to furniture expected.
However, a good alternative is to either provide them with a separate room that is fenced off, or a large playpen so that they can do a little running and binky-ing.
A litter box is also recommended; however, unless a rabbit is feeling sick, their droppings are usually pretty hard and dry, and a hand-held vacuum will pick them up no problem.
