Looks good for high crit/dmg. but I'm surprised you don't supplement the ranger build with Marksman. If you use the marksman tree you can improve all your ranged attacks with increased range, increased hit chance, reduce enemies chance to dodge/parry, ignore armor, increased attack power, marksmans pedastal (18 points in Marksman) increases all ranged dmg by 10%.
It would take some good testing to see if the marksman abilities help your dps more than the passives of nightblade or assassin though but on paper there does seem to be more benefits in Marksman
I would go something like http://rift.zam.com/en/stc.html?t=0M...MofzckRkqz.0VM