speaking of marking down.... up down votes are kinda.... lame? They let people try to speak for the horde so they can get their golden 10k upvote post where EVERYONE agrees with them. Maybe make it just change a color indicator and not show a number at all? Hell, let subs decide on the two colors. Make it valid form of expression, but meaningless. "Duuude, my post was so radically blue man, I guess they all dug it or it would have been kinda green" Sounds a lot less douchy than "Dude I just scored like twenty thousand upvotes for dissing this dude on reddit!"
I don't particularly like how post replies show up as private messages in the message box. Confusing (being only able to see the very last message). This context of a parent post when replying is nice though. Maybe it could be presented (with all parent posts not just one) in some very condensed font in the message viewer for faster context switching.
Also as far as editing, the actual edit box isn't very clearly meant for you to click into it and start typing. #idiotproofing #silvertested #wefakedthemoonlandingitwasreallyonpluto