As you have said both Biochem and Cybertech are good for leveling your main or alts. Regarding the end game, I would say, only Biochem is a little usefull for the reusables but Cybertech has no use unless you "try" to RE the high level armorings and mods. Even if you succeed on REing, you will need to farm rare materials to produce them.
If you only have one character, you don't even need a crew skill but if you need to level some alts, both Biochem and Cybertech are needed IMO.
Edit: For end game Cybertech crafting this topic may help.