you can mix and match direwolf/hellwolf/werewolf healer right side for a full ss right side and naturally you are going to want to make sure all your left side has SS on it regardless of whether you are going for a "spell speed healer".

you are only looking at roughly 50 ss

thats not going to be more beneficial than the amount of vit you can stack

you wont see any noticeable gains in terms of healing output whatsoever and would significantly diminish your suitability, moreso if you play a SCH

real question should be how much mind you are willing to sacrifice for vit and even that doesnt really matter all that much in FL unless you are fighting extended sieges.

As white mage you should be looking to regen players taking damage while efficiently kiting dps, baiting out stuns pre surecast/equanimity and properly using purify for fullswing/trickattack.

and as a sch your job isnt really to raid heal if you're being focused, your job is to keep your other healer up as long as possible while maintaining aetherflow stacks, when you expend your 6 charges, then you start ruin II/aetheric burst and start hardcasting and if necessary using surecast/equanimity. You almost never want to pop your defensives unless you are confident in your teams ability to outzerg/outdps/outCC

The only thing thats going to improve your survivability is
1. learning how kite - smart use of sprint/blizzard2/swiftcast
2. recognizing different types of burst or at the very least keeping track of how many people are focusing you and your allied healer
3. remembering simple defensive cd rotations like rouse/presence of mind used in conjunction with equanimity to counter burst, and if necessary popping more CDs.

I could go on but you should get the idea

If you are healing teamates that know how to kite, they will survive pretty much anything other than a cc lock with 2+ dps on them without you having to excessively bomb heals

If you play a run-to-the-flag and bomb heals till CDs are gone, you should rectify that immediately, or at the very least approach pvp from a broader perspective in terms of ways you can play to increase survivability rather than meeting some kind of dps/healing check through stats while praying your team will outcc/dps