Great feedback. To answer the question about the simplicity of the site and the idea of asking for an email address: Currently, there is no public functionality for you to use. We simply created a page for people to enter their email address if they are interested in the idea and want to be kept informed when it does go live.
But the point that was brought up is great. Currently on some sites, users have to create an account before they can use all of the search tools, or buy an item. We are being very conscious of this, by keeping it extremely easy for customers to come in and find things they are interested in.
As for generating income, we will generate revenue from a final sale fee. We are working on some unique ideas to get around the idea of paying for "upgrades" to a listing. We'll have more information on this as we start to roll out the beta site.
Thanks again for the feedback!