Thanks for this; thethis, I like it.
The proposal's style is as clean and polished as other state-of-the-art marketplaces.
Herestate of the art marketplaces; here are some screenshots:
Apple
Google
Microsoft
Mozilla
On your proposal I would add:
Authors: I like what Mozilla does, Author should be displayed.
Votes: we don't have number of downloads or shiny stars. Votes number is our rating system and it's an useful data for a potential user.
What else?
It would be cool to have the possibility to browse the apps per categories and to order them by filters like Popular|Recently added|Recently updated.
I'm aware that you don't want to customize it too much to avoid to fork the SE codebase; anyway those are my suggestions.