Rotation: Rear wears 3x front. If you put worn rear on front you risk crashing in blowout.
Rear wearing that much faster is not my experience. Maybe 50% faster. And I'm over 200#.
Like on a car, rotating tires should be a preventative action, not a corrective one. Don't rotate because your rear is worn out, rotate earlier to prevent the rear from wearing out sooner. Tire rotation is an economic strategy, not a safety strategy.
That said, I don't put much credence in bike tire rotation. If you inspect your tires regularly, and replace when the tire is unsafe to use, you have done what you can to prevent a blowout. Tire failures usually happen because they're damaged by road hazards or the cord starts to fail (it develops side-side distortion).