FT/FB Clarifications

Hello Esteemed Navigators and Weapons Analysts

There is just a couple of things in the FB book I'd liked clarified.
Under the VECTOR system you have half the Main Drive rating available
for
the manoeuvering thrusters and you can still use all the Drive to alter
velocity.
The example about rolling the ship appears to contradict this. It says
that
a thrust-4 ship that has 2 points available to alter facing (in this
case
rolling and rotating) would only have 2 thrust factors available to
alter
velocity.
Also the VECTOR system says that you only need one point of the thrust
factors to rotate a ship to any facing but the example of movement in
the
paras on Rolling ships and Odd numbered thrust factors imply that it
costs 1
point for each point of facing change.
Now is this a mistake or are the above sections actually talking about
Cinematic movement.
In the optional rule on Aft-arc fire it says that those weapon systems
with
360 degree arc may only fire to the rear arc if the ship did not use
it's
Main drive, presumably as it would be difficult to aquire targets due to
the
interference from radiation and EM backwash (PSB) but does this also
apply
to PDS and class-1 beams used in that role? If not, why not?

Tony
"Eku staras flonderans"
-???? (can anyone identify the origin of this quote, I know it's from a
short story)