They have simply replace
rotateToFacePlanetTRUE
by
rotateToFacePlanet FALSE
If you wish a starbase who always rotate on itself, simply add rotateConstantly True
And yes, it is in some way related to firing... usually, front bank are more powerfull... if the front bank of a starbase is oriented to a planet, that a ennemy is coming, the starbase will begin rotate for face the target and use the more powerfull weapons... it add some delay for the best firing solution... a rotateToFacePlanet FALSE allow the starbase to have his front bank oriented to the entry of the gravity wheel, meaning a more fast response for attack... little detail who can change a lot at the tactical level
I doubt that, because according to the files, starbases have equal dmg on all sides. just dl the forge tools 3. there is a directory with reference data where you can look it all up. front, back, left, right all have the same values for all banks.