2. My system isn't an alternative to perfection, it's an alternative to democracy which is decidedly imperfect. Intelligence is likely a better proxy for pro-social attitudes than the ability to navigate political institutions and then trick a bunch of people into voting for you.
3. Again, compare this not to perfection but to what we currently have.
4. Training for IQ tests has very limited returns. But as I specified, the test will be used outside of politics, too. In fact its most common use would be by academic institutions and employers. Because of this, most people will have incentives to train to whatever extent possible. Thus the test becomes slightly less G-loaded and slightly more a test of conscientiousness, but any plan to train up a bunch of corrupt lackeys would have very poor expected value.
5. Again, compare not to perfection but to what we actually have now.
As if democracy didn't have enough struggles, telecommunications (and especially television) have forever changed the way that the people choose their representatives. Superficialities are much more important now than they were pre-1960, and everything we get is filtered through the media outlets that control the television broadcasts; if they dislike someone, all they have to do is repeatedly re-broadcast a single unflattering yelp and that person's prospects are done. [0]
We need to learn to deal with that.
1. IQ test has been shown not to represent actual "intelligence"
2. Intelligence does not mean justice, fairness or anything else.
3. Conflict of interest. What if the so called "most intelligent" people have some interest in the voting?
4. Trainning. I'm pretty sure anyone could end up in resulting a genius by trainning on problem sets for IQ tests.
5. Being smart doesn't automatically make you a good people. Smart and asshole are not mutually exclusive.