People are just looking for a scapegoat. Jamie does a fine job as a PA announcer. He's even better at hockey then he is at football.
Like other said, he is not responsible for the ads. Blame Maturi, or the marketing department, but don't blame the PA guy because he does the ads he is told to do.
As for the ad during the play, that was mistiming by the BTN and the red hat guy. They were the ones coming back from commercials early which is why somethings appeared to be late, like the ad during play, and the dance team false start. The pa guy has a script in front of him, and again, its not his fault if things are changed and he isn't told.
Like everyone rational has said, its a whole gameday operations issue. Poor communication, poor scheduling on inbetween timeout activities, and then the copious amount of ads. I guarantee you that unless some big donor steps up and donates multiple million dollars to cover the missing revenue achieved from the gameday ads, they will continue. Its all about the $$.