In Zen Cart v1.3 the default checkout does still require the customer to create an account. That may change in future versions.
Everything else in checkout is information you WILL need to collect from the customer ANYWAY, so you are free to alter the wording of the content on the pages if you don't like the way it's presented.

There are some addons that have met with mixed degrees of success in altering the presentation of the content depending on the individual storeowner's need.