Wow flash! You really thinked about it.

I disagree with beeing invincible when chatting because you can use that in a bad way like this for example: You see 10 seekers coming right toward you. Then ofcourse you starts to chat without chatting and will not recieve any damage.

O and couple thing for JCS:
-beeing able to play the music you wan`t in your level.
-If boss appears that you can do that there will be no boss music.
-Lori start pos
-Beeing able to export the tileset into bmb and the mask.(or something different like .JPG)
-When coin warp used the coins don`t change into gems.
-beeing able to let layer8 move

For MP:
-kick vote.
-Level voting system like in UT2004.
-chat smilies.
-When someone has sugar rush you can see it.
-Team battle

O and one more thing for the serverlist:
-Beeing able to see how many players there are in the server and who is in that server.
-when you host you can type a text and all players who join your server see that text for a couple of seconds. (So you can tell them rules for example.)

That`s about it for now.