On Commissions: Many states prohibit agents from pushing insurance. They cannot hard sell you. The reason is that they are not insurance agents. In Hawaii it is against the law to pay them commissions, as they are not licensed insurance agents. This came as a result of an overwhelming number of complaints from customers to TV news, consumer protection and legislators. That being said, I am sure that companies monitor what their employees do and if someone sell a lot of insurance....well.
If you have an American Express Card, check out their Premium Insurance Protection. It covers your rental for $24.95 per rental, not per day. It also takes first position if there is a claim and your personal insurance premiums will not be affected. This is from personal experience.