This can vary quite a bit employer to employer. As a contractor I've always successfully crossed out indemnification clauses, noncompete clauses (except while the contract is in progress), and anything that lays claim to my time or effort outside of work. But I've also been willing to walk.
You have more leverage as a contractor I think, the position is different to an employee. Clauses like noncompetes and IP claims outside of the contract are a pretty hard sell for a contractor, as it limits your ability to work after the job is done and as such it's going to be hard to hire a contractor with those kinds terms. I imagine clauses like that are designed to keep employees around for as long as possible, not really an aim if you're hiring a contractor.
Depends on the goals of the contractor. They might concede to some crazy agreements to be able to list a big name company or a high profile project on their work history to get higher paying work in the future.
