The title commitment is not optional. It is what it says - a commitment to issue a policy, provided certain requirements are met and subject to listed exceptions. The policy will not be issued until the requirements are satisfied. Any exceptions not cleared will be shown on the policy.

The lender would never purchase an Owner's Policy. It does not give any coverage for the lender that is not already part of the Loan Policy. The lender can get an Owner's Policy through a foreclosure proceeding, depending on the state and the products that are offered by the underwriters. 

A refinance/secondary mortgage transaction would only have a Loan Policy. A cash sale/land contract would only have an Owner's Policy. A sale with a new mortgage would have both policies.

Fees are variable and state specific. Some states allow for charges for title searches. Some only allow a single charge for the initial search, commitment and final policy. Policy charges are also dependent on the type of property and the amount of insurance requested. Furthermore, policy charges are set by the Underwriters, normally with the approval by the state, as they are regulated fees. Closing/Escrow fees may or may not be regulated by the state.

If you want to know if you can make money as a title agent, I would suggest talking to a local agent to learn more about their trials and tribulations.