You aren't pigeon holed into anything. Hit 110 on your alts, queue up researches and check them every day or two. By the time you are in the mood to play them competitively you'll be at a high enough Artifact Knowledge to be able to get your weapon up pretty quickly. Want your item level to be higher then do World Quests for free relics or get one of the profession ones. Do them now for the first time and it only takes a couple days for first couple ranks then it starts going back to where it's caught up. Heck if you don't play it all expansion and just keep it queued you'll hit 24,000%.
Not sure why you want them shared. Have we ever had gear shared before? Nope.
They won't. That's how they time gated it this time. They want the Class Hall Campaign to take X amount of time. They actually wanted it to take as long as the warriors, but they messed up and had to bring the warriors in line with everyone else's in order to be fair.