So, I was thinking about this as I was walking to the bus to get home (I need a life, I know) and thought about some suggestions for additional stances for the Arcane Archer to improve their range ability. I draw from the current stance of Imbue Force, which deals an additional 1d6 force damage and makes all shots ghost touch. In effect, it deals additional damage (unmitigated against most monsters) and bypasses an ability. So I suggest two additional stances to choose from at the same level and AP cost
Arcane Archer: Imbue Concussion
Usage: active
Cost: 1 action point
Spent: 18/30 action points
Requires: all of Ranger Arcane Archer I/Elven AA I
Available to: ranger 6/elf 9
Benefit: Imbues all missiles that you fire with arcane concussive blasts, granting them the concussive ability (+1d6 sonic damage) and transmuting the arrows damage into blunt damage for purposes of damage reduction. This ability costs 10 spell points to activate, and triggers a lengthy cooldown of the shout spell. Only one Arcane Archer Imbue ability may be active at any time.
Arcane Archer: Imbue Broadhead
Usage: active
Cost: 1 action point
Spent: 18/30 action points
Requires: all of Ranger Arcane Archer I/Elven AA I
Available to: ranger 6/elf 9
Benefit: Imbues all missiles that you fire with arcane broadheads, granting them the slicing ability (+1d6 bleeding damage) and transmuting the arrows damage into slashing damage for purposes of damage reduction. This ability costs 10 spell points to activate, and triggers a lengthy cooldown of the Daze Monster spell. Only one Arcane Archer Imbue ability may be active at any time.
The idea behind both is that this grants an Arcane Archer the ability to bypass some form of damage mitigation (either ethereal, or blunt/slashing dr) while also giving an additional form of damage that is rarely protected against via resists, inherent abilities, or ability to bleed. It also gives ranged characters a way to bypass the dr of monsters that doesn't involve piercing. These stances could also be placed in the same situation as the rogue assassin poisons: one enhancement that grants three different options. But I'd boost the AP cost of this method to 2 AP for all three.
Just my 2cp