My bad for not actually checking for similar proposals in the forum..
Participating at the game as an observer would not really be good imo. I guess it requires consistent work to implement and also would introduce various secondary issues.
I know about the Uservoice but I first wanted to see if the interest was even big enough to go through that way. I am aware the Uservoice war is not an wasy one to win..
For anyone interested, this is an old uservoice of the idea
http://warlight.uservoice.com/forums/77051-warlight-features/suggestions/1920689-partial-history-see-what-only-one-player-could-s