1. This is factually untrue. The same argument is made against raising minimum wages IRL and it's a myth. Raising wages does not generally increase cost of living. In countries where the minimum wage is greater than double that of the United States, the cost of a Big Mac, for example, remains almost unchanged. Considering you're talking about basic economics, consider looking up the Big Mac Index.
2. It's also more exciting - this isn't really a disincentive as far as I can tell.
3. That's... just not a great argument, I don't know what you're trying to say. It doesn't make sense that a roadworker can make more than a lawyer or doctor or cop.
4. I don't really care about the tax one way or another.
5. I... sincerely doubt that. If anything it'd raise the general quality of RP if that was to become a factor.