Shipping costs is handled by USPS based on weight and location, and can be easily turned on and off. You can turn it off and create your own shipping with eCart.
It does not handle discounts, so that could be added with eCart and Dreamweaver as well.
This is the first powerstore version, so we haven't explored or added some of the common features yet. We will be working on improving and expanding capabilities using eCart and Dreamweaver ourselves and hope to include these features in future versions.