You're right, I accidentally grouped Artifice and Armstech together thinking they worked hand-in-hand like Armormech and Synthweaving. But yes. Armstech < Biochem < Artifice < S/A < Cybertech at the moment.
actually i disagree a bit
Armstech - true - useless
Biochem - even after the Nerf still the best crewskill around - if your an PVE endgame player (The dropped Biochem Recipies are now worth something!) - for PvP depends on your cash stockpile but still useful.
Artifice - apart from Augment Relics not that usefull atm (make and relearn)
S/A- same as artifice
Cybertech - ok but not that good after the grenade nerf.
as far as the Biochem nerf goes in general:
imo the only way to go - was just unreasobale before, seeing as the dropped Raid-Recipies were worse than vendor bought ones...