Thank you for asking this question — its OK to ask here in the forum, you’re right – maybe someone else will have the same questions.
You can absolutely sell your services with the theme, its totally up to you. You can customize the theme a little or a lot, totally up to you. What the license does is grant you 1 on 1 support with us for standard theme questions — by that I mean questions about the basics of how the theme works, not something you customized that might not be working. So, for example, if you setup a Winning Agent Pro site for a client, the client would need to contact you for support and not us. If you needed help, then you could contact us since you purchased the theme. Does that make sense? In regards to the Genesis Framework, we always recommend purchasing that directly from StudioPress so the client has an account with them for full access to their support, code snippets, etc. You can always use an affiliate for your clients for this purchase.
In regards to IDX, it is up to you if you want to sell IDX services are part of what you offer, it has no connection with the Winning Agent Pro theme. That said, since Winning Agent is an IDX Broker partner, we offer a killer deal. Have your clients purchase IDX Broker through us and their setup fee is waived and we will style their search bar for free (normally a $99 cost).