Another way: Voting power by some logarithm of fraction owned of all coins, weighted by account age. The latter discourages endless scattering of NXT to circumvent the logarithm (which would be a real problem in a naked log system).
Smaller, but older accounts could be on par with new big accounts in that system.
Makes no sense. Anyone can split his coins into smallest parts. With log-scale it gives him even more voting power

There'd not be global voting at first place. We're already voting, Every time we're clicking "I'm agree" or every time we run binaries, or... I hope u got me.