I think the reason for the sch / sum split is because SE wanted to rework the healers and they probably couldn't do that effectively without the changes to sch effecting sum as well.

Removing the piercing debuf from dragoons it probably not the first debuf that is going away, I have a feeling that the slashing and blunt ones will go too. I wonder if bard / mch will get buffs as well as the dragoon?

The rez limit and no rez sickness sound like a good idea, it makes things more punishing for continuing to make mistakes.

Yay tank stance is going away too, it was a useless ability that only punishes tanks for using it, but the loss of strength on tank gear I'm not sure about