BuddyPress.org

there are several themes such as P2 and Prologue that offer front page posting.You can use TDO forms to have a form on the front page to post.I dont know if it works with mu..give it a try.

What i tried to point is that you can use the same technique in your themes, so as to avoid users to log into wordpress panel.

This can be done like this

if( user is blog owner) -> show the quickpress code (you can copy the quickpress code from the P2 or Prologue theme)

else

show the comments form

its the basic logic.I am working with my initial setup,i thought to implement this later when i am finished with my setup