In addition, it seems that you are going for the more "fair" system, but by setting a minimum NXT holding limit, aren't you excluding all those who have less than this amount? So small stakeholders are being disenfranchised even more so than the 1 NXT = 1 vote system.
Do you mean with 1 NXT:
1) 1 NXT in balance
or
2) 1 NXT fee
Either way. People with larger stakes will care more about what they vote on whether or not they have to pay for it.
I would say it is better to be based on 1 NXT = 1 vote (without pay), otherwise it will discourage voting. We want a large as possible agreement, so that means we want as much NXT in the system voting as possible.