Too much in this thread to churn through, but has anyone suggested hybrid situations regarding the Level Sync? It's nice for those of us who play at weird times and generally have to solo to be able to decide if we want the mobs to be a challenge or not. It's nice to be able to go back to Heroics or Flashpoints that were missed and just be able to blaze through them to get the story bits or some custom gear (even if way low level). But under certain circumstances, particularly class quests and any time you're in a group, Level Sync should *NOT* be optional. If you have a group, then you should have the proper challenge and not-too-uneven XP distribution. You should always have the proper challenge from class quests. For anything else? Meh.
Usually when I do flashpoints with a group, we have to rush through them, skipping conversations, bypassing whole sections, etc. I like to be able to go back to these and just enjoy the story bits at my own pace. Level Sync would have made it impossible for me to ever get to truly enjoy the story arc of The Foundry, for example (not that it's that great, but it's fun to see some old faces and actually savor the dialog). If I'm way over-level and gain no XP as a result, I'm fine with that, as long as it's my choice. Sometimes I'll want the mobs to be a challenge, sometimes I just want to plow through. Give us the option during solo play, and everyone's happy.
I'll reserve judgement on the companion changes until it comes out, though I'm not over the moon about those either.