thanks gya.. that peaceful aura is really counter-intuitive. 50% threat reduction is really alot to me. plus not mentioning having dispel but cannot utilize it in the 8 slots. kinda really hate bioware for this.. on rejuvenating barrier, cant we have it on 2nd mage and still have the benefits applicable for KE? or the benefits must be that from the caster? i also think static cage cost alot of mana. if the KE is the caster, plus he definitely needs energy barrage to maximize the damage output on number of hits for that short 8 secs duration. Spirit Blade animation is just too slow and now the nerfed version 150% damage vs the old 400% really useless. I also think Bioware is kinda stupid to nerf an SP game.
as for fade cloak.. i don't know why i dont have good impression on it. tell me what i'm doing wrong. i play the game mostly on tactical (not real-time). it's really a pain in the arse that for that short 2 secs i have to manually ensure KE will emerge and rematerialize inside the enemy's body for that 1000% damage. i often wasted that 1000% damage. also why statis lock instead of charged disruption? i see charged disruption much better at least it will recharge the blade faster and i think when with the disruption field and everyone attacking the mob inside the field, KE can just spam SB for free for that short few secs.
I believe that rejuvenating barrier only works with the barrier that was cast by the mage with that passive. This means that your KE barrier will overwrite it and you won't benefit. I'm not 100% sure on this, I seem to remember someone had tested it but I can't find the post. If you have Trespasser, then the sigil of the great bear will offset the mana issue somewhat.
Spirit blade can be recharged very quickly as you use other abilities, especially energy barrage. That said, I personally only used it a few times per fight, mainly to strip guard, since it still retains bonus damage against them IIRC.
Not having dispel shouldn't be an issue, just stick it on your other mage. Or, as AlanC9 says, you can swap it in if you're about to close a rift. Against the randomly promoted mages, that's often not an option because you won't know they're promoted until in battle.
Regarding fade cloak, I have to agree with PapaCharlie9, it's best used out of tac cam. Decloaking blast is not absolutely necessary though. In fact, no real level of min/maxing is needed unless you're soloing, and even then, the toughest parts of the game are the first few hours and the DLC boss runs.