Multisite and marketpress: creating an etsy like site

I am wanting to create new sites for users on a multisite platform with marketpress but would like the new site owner upon completion of registration to have a simple template to create a storefront and participate in forums but not access to the full dashboard. I've already enabled multisite and marketpress and tested out site user registration. All good until I saw how much capabilities the new site user would have. Way too complex for what I'm hoping for. Instead, I want the users to all have a simplified experience, just filling in a profile and setting up products in their simple store front page. Also, I want the global product categories to stay static and not have site users creating their own categories but instead showcasing their products within a set list of categories. Finally, on their simple storefront page, users would have easy links to their selling and purchasing statistics and group forum discussions. The main site would have policy and terms of use, and tutorials. and a way for non registered users to browse shops and products. Any help would be appreciated.