To address the mass not being taken into consideration:
Force = mass * acceleration
The units with the physics behavior is off by a factor of 50 or so. In practice that only matters if you want to use exact units. Most of the time you can just tune the numbers.
There is no solution for the sleeping with what the physics behavior provides access to. If you can somehow access the underlying physics engine from JavaScript there may be a way to do it, but the behavior wasn’t designed for that, and you’d be fighting with the behavior.