Undocking question

When the shuttle undocks from PMA2, springs push it off from PMA2.
(according to NASA TV commentator).

Unless the docking collar happens to be at the centre of gravity/mass of
the shuttle, wouldn't that push put the shuttle into a slow rotation ?

I take it they use vernier thrusters to compensate and give the shuttle
a nice trajectory away from station that retains same attitude ? How
soon after the undocking do they do this ? Is this done "by the seat of
their pants", or do they have precise instrumentation to fire the right
thrusters for the precise amount of time needed ?
.