Now that I finally have all orc items, do I need to activate them all to receive the "full orc" achievement, or just left them deactivated?

When you have all the Orc items, the achievement should be gained even without activating them all.
You don't get it immediately, though. You should wait around 24 hours before you get the achievemtn.

Ok, thanks
I'll wait

The avhivments are still in a beta version. If you do not recive it, that can be expected. Pm skulfuk or slipanc or any other admin/moderator

Orc achievement shouldn't be broken.

Anyways, closing.