Its funny you know. You have 2 perks from biochem.
1. You have the best possible stims
2. They are reusable.
Bioware is taking 1 of them away to bring them inline with the others. Artifice have rakata relics that u can chuck an augment slot in, Synthweavers and Armourmech can craft rakata belts and bracers with augment slots.
No. They are taking both. Reusable stims are crap now and you have to use single-use ones for min-maxing. Those single-use ones are now tradable. So no advantage except of no cost at farm content.
Artifice/Armstech: Crit'd Relic. No profession-lock on equipping, so you can unlearn afterwards.
No, armstech has nothing as far as I know. I unlearned this profession because you have no epic recipes, no bind-on-pickup items, just NOTHING.