I caution some against opining about things outside of one's experience. There are alot of issues here, but a couple of thoughts. The "severability" clause (if one provision is thrown out, the balance of the agreement is enforceable) is standard form stuff in most contracts, and not an issue. The negligence waiver is more complicated. It is certainly perfectly acceptable under applicable legal principles to contract away any right to sue for negligence. Happens all the time. However, courts in the US and some other countries don't love these things, especially when applied in egregious cases. The arguments for throwing the clauses out (or limiting them) typically have to do with (i) the fact that the form is a one-sided contract (contract of adhesion) that is not negotiable and so is not really an "agreement", (ii) in some states, more general arguments about such clauses being against public policy in the context where operators are making money by engaging people in a risky activity, and so they need legal liability to make the operators keep their acts together. In any event, you will not have any luck attempting to change the form, unless the operator is desperate for the business, in which case you should shop around anyway.