Disclaimer: I'm rarely on the forums so if this has already been suggested then ho hum.
Hold your horses folks, I know what you're thinking - "WAH I don't want random people watching me get glorped by jellies!"
So what if there was a toggle like the already existing toggle that allows friends + guildmates / just friends / just guildmates to join your party but for toggling who can spectate your run?
I mean the spectate mode in the coliseum is great, especially now with the map overview but why not extend to the clockworks? It sorta exists already if you're in the party and dead since you can cycle through the other players' perspectives.
Spectator chat could be open during the lift between depths and/or during the end report of a tier / mission.
Think of all the drinking (responsibly) games you could play!
I'd quite like something like the Lockdown spectator system, where others can view but not play. +1 to the idea if that was sort of what you were going for.
EDIT: Only if it's completely toggle-able so you can control who can watch you. I like the concept of being able to have friends who have nothing better to do watch you, so you can talk to them while playing.