Re: Combined Register + Post
If your concept of the site depends on this plugin, you may want to consider hiring a developer (like Kawauso!) to build and test it for you…
Regarding waiting for the password over email – you can address that with this plugin! I use it on all my sites and can vouch for it:
https://bbpress.org/plugins/topic/instant-password/
This may also simplify the registration process… I haven’t used this one yet though:
https://bbpress.org/plugins/topic/openid/
Good luck!