Stamplar sustain is really bad. It's seriously hampering my enjoyment of the class in battlegrounds in particular, because I can't sustain without CPs. Medium armor is useless as a primary setup in PvP (at least for templars) so I've been using 5 heavy 2 medium. I'm using Eternal Hunt (2x regen), Bloodspawn (1x regen), and agility jewelry with three sustain enchants but I still can't keep stamina. Heavy attacks are useless in this scenario as well because they're hard to land and other people won't stop their damage to let you restore stamina.
So a simple suggestion; change Channeled Focus in the same way spears and orbs were changed and make it restore your highest resource pool instead of just magicka. Maybe even give it a very small restore for the smaller pool as well. 10-20% of the primary or so. That would encourage versatility in PvP because magicka templars in light armor are a joke with no stamina sustain.
EP: Slania Isara : Harambe Was an Inside Job