[Flaser]

AFAIK damp simulates the mass or the existance of mass of the object.

For acceleration you just use the whole mass value.
A = F / m nothing fancy, but since it is a constant and so is thrust, it was easier to code just acceleration.
For rotation though an object has a rotational inertia. It is the sum of the mass * the squaro of the distance from the axis of the rotation.
Therefore the ship has 3 distinct inertia against rotating an all axes - therefore they introduced damp as a factor of simulating this.