1. Archer rangers really ought to be on the front lines anyways, or at least skirmishing around, to get that Prime Shot advantage. And yes, to absorb some damage and keep the heat on the melee guys a little lighter. They just have the convenient option to NOT be on the front lines if they decide they don't want to be.
2. Most of the powers are fine, not particular great or terrible, but usable. Though I don't like the level 6 one. Its another one of those ones that can lead to outcries about the martial power source being too magical. I can only really think of three or so of those in the entire game, but I don't particularly like them and I really, really don't like listening to people try to make Grand Unified Theorems about 4e out of their presence.
2. Most of the powers are fine, not particular great or terrible, but usable. Though I don't like the level 6 one. Its another one of those ones that can lead to outcries about the martial power source being too magical. I can only really think of three or so of those in the entire game, but I don't particularly like them and I really, really don't like listening to people try to make Grand Unified Theorems about 4e out of their presence.