Please describe what you believe he's wrong about. He's not wrong very often, and when he is he likes to correct the site immediately.
3. The electoral vote system does NOT somehow restore the balance of power between big and small states, allowing the small states to have more say. (That goal IS accomplished by giving each state 2 senators, regardless of its size.) That is because the number of electoral votes a state has, which is the same as the number of seats it has in the House, is (up to roundoff) proportional to its population. Thus this system simply introduces more noise and more risk of unjudgeable cliffhanger elections, with no compensating benefit.
Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress: but no Senator or Representative, or Person holding an Office of Trust or Profit under the United States, shall be appointed an Elector.
Yes, models are imperfect. But Smith used 720 different combinations of the 5 fundamental parameters in his simulations, and then got the average utility efficiency for hundreds of thousands of elections in each of those combinations. Score Voting won in all of them. And by a pretty good measure. It his hard to conceive of any obvious flaws in his simulations, whose correction could possibly make up the difference. Therefore I see those figures as being extremely reliable.
Sure. Some people will think your simulation should model a society of 10% strategic voters and the rest expressive. Other people will believe that at least 60% of voters are strategic. So you just do simulations covering all of those values. If Score Voting wins under some models, but fails in other models, then you have the very tricky task of figuring out which of those models were closest to reality.
Yes. You can more or less prove that. http://rangevoting.org/UtilFoundns.html The most compelling "proof" of it (aside from the fact that most every other social utility function can be disproved via reductio ad absurdum) is Harsanyi's observation that a rational voter should want the system that maximizes his expected utility (do not confuse that with expected value, since utility and money are not linearly related).
Here's a voting method that employs revealed preference: http://rangevoting.org/CTT.html