re: 2, the issue is that e.g. airport gates are a(n artificially) limited resource that require airlines to perform behaviors that don't benefit customers and have externalized costs (e.g., wasting fuel) in order to maintain access to those resources.

A bus only needs to have something like four people aboard to make it more efficient than equivalent cars by most measures (road space required, fuel, etc); so it's not a 1to1 comparison to other transit rates.