WP e-Commerce extension that allows you to add simple "product options" to products without having to create or manage variations
It's likely that your theme doesn't include the hooks you need. You'll need to ensure that your theme contains the standard WP e-Commerce hook "wpsc_product_form_fields_begin". You can see the official WP e-Commerce version here, in wpsc-single_product.php here: https://github.com/wp-e-commerce/WP-e-Commerce/blob/3.8.14/wpsc-theme/wpsc-single_product.php#L77
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
No, if you want the product options to affect stock, or pricing then you should use WP e-Commerce's built in "Variations" functionality
Product options are shown against the sale under Store Sales in your WordPress Dashboard menu
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.