To prevent people raging at suiciders, why not make a MAXLEVEL = all the levels of every person in the team. Then, if the surviving levels at the end is around 32%, then the team gains +2 multiplier, or +4, depending on the max multiplier.
This gives people who spent more time in the game, compared to a peasant, more control over the multiplier they gain, but they also will be risking a higher % chanche of your the team's maxlevel if you die, than when a peasant dies
I really love the rest! Nicely thought out.