Is the SCOPE any good ? (visually it looks less than impressive, but is it justified on its stats...?)
Depends.
On Executioner, it offers about 2.6x magnification (increased from about 1.3-1.5x)
On TK Aphelion, it offers an increase from 1.3x to 1.6x - not as nice as above, right?
On weapons that dont have a scope already, it helps with scatter - most useful on Intimidator, not so much on anything else (although it may still be useful on Oppressor and other automatic weapons)
What about the GREATER SCAN RANGE ... is that a good mod..?
It increases ID range from 50 to 100m and make it almost instantaneous. No effect on cloning ID range
Is it worthwhile adding HEADSHOT to Scope and Long Range...?
again, it depends.
Headshot doubles the damage - if you can actually manage to do a headshot.
I'd say it is useless on Executioner (and maybe other plasma weapons, except maybe the Oppressor)
It could be useful on a P-15 which has a quite nice damage at G5, still it's not enough to one-shot someone, it still requires at least 2-3 shots
It could be useful on a TK Aphelion (along with scope, range and increased magazine size) - for long range kills without needing to swap to kinetic weapons.
And also maybe on TK Zenith - again, for the same reasons, killis without swapping... but only for die-hard-Lazors fans... esle a Tormentor is the best overall weapon.