For what any of this is worth:
You can fly over or under them, but it's *very* high/low.
About 3-4 screens-worth of height, so try going farther before trying.
Also, if you're trying for over/under, don't press directly on the waypoints until you're close to them.
iirc they are coordinates also for the Z-plane, not just X and Y.
They
can drop the tier 3 pulse laser turret, I forget its name.
Not too common, though.
I understand that you're getting killed by the turrets, not the script?
Is it your mothership or your fighters that get fragged?
(The fighters try aggroing the turrets if left unattended.
Too dumb to live, I guess.)
Try:
Choosing the other option (where you pull in an NESF patrol to engage the turrets).
For bonus points: if you have torpedoes you can killsteal the Stone Arrow ;P
Disabling auto-launch fighters.
When Ternie wants to pull one, launch *just her* and bring her back.
There is, iirc, a large (bright pinkish?) asteroid inside the turret belt.
Aiming for it should get you through the turrets unharmed.
Zooming in on the tactical map allows more accurate movement, not that it matters in this case, since the waypoints are specific locations.