1. I already gave an out for your point. Yes, always weigh performance vs. clarity and don't over optimize.
2. You are making an assumption that you aren't binding thousands of times a second. You need to take actual use case into consideration.
3. My example has a 1000:1 method call to bind ratio and it's still a significant difference in benchmarks. Yes, it's that expensive it's important to think about in critical sections of code.
They're not expensive. You're not binding thousands of times a second anyway, so stop your silly premature optimizations.