The effort is noble, and the concept of introducing friction in order to lesson the effect is understandable, but the changes proposed as some have already noted would not gain the desired outcome.
The only way anything works to lessen this effect is to have ID Verification... no matter how many ways you slice it, every solution to this comes back to the ability of tethering ones voter balance to his identity... only then can you put parameters around how much they can vote.. the most fair in my estimation being changing voting from 1:30 to 1/30 and causing the weight of their stake to distribute instead of having full power on every vote. Yes, they could vote for themselves in that case, but they couldn't affect huge control over all active 21... and that is the real issue.