There are other things to consider as well.

mechanic gives raw damage to repeaters, but you lose deadly.

Ignoring Runearms shots and offensive casting does 2 things for a build like this.

1st you need different gear since you only need spell power for healing. This lets you focus everything into ranged damage and survivabiliy instead of ranged, survivability, & offensive casting

2nd only using Spell points for buffs and self healing they go a long way making it less dependant on shrine.