1. Absolutely valid point.
2. Disagree. Sure coaches are biased. Sure they have a stake. Which is why you don't act on ONE coach's word, but consider multiple assessments by multiple coaches over time. As I have suggested here.
3. Agree, to a point. Because referees, too, can be biased, you develop a similar system for referees to evaluate schools' "game management." When there is a PERSISTENT problem, cited by MULTIPLE officials, the SCHSL (or whatever governing body you choose) levees fines/suspensions/both. SYSTEM IN PLACE FOR ALL SPORTS. If you've ever been to a high school basketball game, you know that the "abuse" you take in soccer is NOTHING compared with the environment in other sports.
4. Agree. But first, let's institute a valid (or at least better) system of evaluating officials, and reward those who consistently grade out best with better pay.