The TNG and DS9 Tech Manuals are not CannonAccording to the TNG Technical manual, the effective range of phasers is exactly that, 300,000km.
The Bane of Trekys Everwhere is while EU(Written supplments in the form of Books and ICS's) ARE Cannon Evidance(IE they are real and endorced by the assoative parent companys) in ST its not
ST Cannon is very simple
Movies
TV Series
NOTHING ELSE
As for your second question
ICS, Increable Cross SectionsIs there a tech manual for the SW universe? I'm curious to see what it says about weapon strength, shield strength, and ship capabilities in the SW universe. Any recommendations?
And WEG, West End Games Supplments no Longer aviable for purchase however avaible Online