General note: need to specify subclasses, and cleric deity. My assumption: Archer, Inspiring, Moradin (?)
1. Looks fine to me. You may want to consider Half-Elf, so you can pick up Piercing Strike as an At-Will (Dex vs Reflex is very nice)
2. There are much better feats than Defensive Mobility. Consider Enlarged Breath or Toughness. Otherwise, good.
3. I question the Ability distribution. While it's possible to dump STR, it will severely restrict your choice of powers. Take at least a 10, so you can melee in a pinch without the -1 to attack and damage. Also, why pump CON so much? None of your abilities are keyed off of CON. I would take: St:13 Co:12 Dx:10 In:8 Wi:20 Ch:13.