The anchor runner carries the baton the shortest distance of the four. All things (like starting ability and curve running) being equal, ideally your fastest runner should lead off--the first runner carries the baton the longest.
Incorrect. How long your run depends on where you get/give the stick in the zone. The first runner only runs farther than the last runner if he hands off at the end of the zone and the anchor receives at the end of the zone. Second or third leg can run longer because they can receive at the beginning of the zone and handoff at the end. You don't put your fastest person first. You put your best starter who can run a curve well first.
Brommel anchored because the U.S. thought they would have the lead that way. They were wrong.