Frankly, I think new player retention is low in the game because of the rampant Cronyism, or the perception of such. If plot does nothing to curb the perception that only 1 or 2 groups of players are not only getting all of the loot, but getting all of the story and everyone else is just there to spectate and witness their greatness, then new players are not going to stick around. It is the responsibility of Plot teams to engage new players and give them something to do and fight against that is their level, rather than only catering to high level players who apparently can't keep on their own side of the field and have to ruin everyone else's fun....
New/different rules aren't going to change these facts. Plot especially, but also current players, need to engage with new players and allow them their fun. That is the biggest reason new players leave, not overly-complicated rules.