@jamesbrown - It is an interesting proposal. It is always good for us to brainstorm and try to think of ways to improve the platform. As far as the limits on voting, the main reason is to prevent people from gaming the system. If people could vote on things as much as they want, and use their full voting power every time - then people could cause the reward pool to be unfairly distributed. The issue with time limits is that there is no way to enforce them while still running Steemit as a distributed blockchain.