interesting thoughts.
I think reputation is another interesting modifier.
I've thought for a while that Hive accounts should have a slow moving long term rep and a volatile short term rep which determines the speed and direction that the long term rep is moving in. That way you have to stay active and be considered a positive force by the community to maintain your rep. I think this could/should also contribute to governance stake. Like you said, in order to game the system, the accounts should have to do all the things which align with the network, but as a community we should also be able to sniff out bad actors and limit their voting weight.