WordPress.org

The options chosen are supposed to be displayed during checkout - where are they?

The current stable release of WP e-Commerce doesn't have the hooks to allow external plugins to display info like this during checkout. They're coming in a future version - watch this space

Can I change the price charged according to the option chosen?

No, if you want the product options to affect stock, or pricing then you should use WP e-Commerce's built in "Variations" functionality

Where can I see which product options have been chosen

Product options are shown against the sale under Store Sales in your WordPress Dashboard menu

Can I order the options as they're shown to the customer?

Yes, install a taxonomy ordering plugin - I recommend http://wordpress.org/extend/plugins/taxonomy-terms-order/ Once you've set an order in the admin area, that will be honoured on the front end.