12 seconds from Throttle advance to liftoff? You'd have to be flying that 737 real empty, or with a 60 knot headwind. Typical is what, 30-35 seconds?
I don't know about the NG, but the retrofit Forward Looking Windshear systems were turned on by oil pressure on at least one engine, and Transponder out of Standby. I can't imagine why they would have changed it.
Weather radar nuking ground crew? Forget it. The average power from a modern Wx radar is less than one watt, as opposed to your home nuke with about 700 watts. The DMEs, ATC transponders and TCAS all radiate equivalent power to the Wx radar.
GB