I don't think he is presenting himself as a .400 hitter, or expecting the applicants to be. He just thinks that they should know which end of the bat to hold.
Yeah, I know. It's still bad form to castigate others for making mistakes while you're making one in the process.
I do agree with him, though. I'm amazed at how so many people can't figure out the difference between "they're," "their," and "there."
Yes. It is rather like using “U” to represent “You”.