Concentration RA [resets quick cast cooldown to 0] could use a little help.
I suggest:
Concentration 1 : 10 mins cooldown
Concentration 2 : 5 mins cooldown
Concentration 3 : 2:00 mins cooldown
Concentration 4 : 30s sec cooldown
Concentration 5 : 15s cooldown
[currently it is: 15, 9, 3, 1:30, 0:30]
I think 15s would not be 2 crazy, even not for a necro at conc5, for how much it costs. 10 mins would mean it's up most 8v8s, 5 mins = every 8v8, 2 mins = twice in a good 8v8.
Initially I was going to say you're fucking crazy for suggesting 15s reuse but maybe not.
The strength of Conc5 is that 30s matches your Quickcast/Facilitate Painworking's RUT- meaning every 33 seconds a caster receives double Quickcast and 35 seconds a necro double Facilitate Painworking.
With a 15 second RUT the user initially gets the double QC/FP, and then 15 seconds later a 3rd. But using Conc at that point prior to QC/FP refreshing on its own means you do not get a double QC/FP that time around.
To better demonstrate for those've never used Concentration:
Quickcast RUT is 30 seconds
ConcV RUT is 30 seconds
You burn a Quickcast, it's down for 30 seconds. You use ConcV which refreshes Quickcast. Conc's 30 second timer begins immediately, however Quickcast doesn't start until you have used this 2nd Quickcast. This means ConcV's timer will be ready a few seconds before Quickcast is ready again. Using ConcV as soon as it's ready gives you the 3rd Quickcast a few seconds early, but since you just used ConcV to refresh it, there is no 4th Quickcast until the next refresh. If after your first double Quickcast you instead wait for both ConcV and Quickcast to refresh you get a double Quickcast again. The fact that you have to wait for both timers is what causes the longer-than-30-second wait.
Now doing that same thing with the revised Conc:
Quickcast RUT is 30 seconds
Conc RUT is 15 seconds
You burn Quickcast and refresh with Conc. 15 seconds later you refresh Quickcast immediately, giving you your 3rd Quickcast within 18 seconds. At this point Conc will be ready again in 15 seconds but Quickcast will not be ready until 30 seconds after it's used... which means using Conc immediately grants you your 4th Quickcast at 33 seconds. The price of refreshing Quickcast without waiting for it to first refresh itself is again no double Quickcast. The condition for performing double Quickcasts with a 15s Conc is identical to 30s Conc.
A 15s Conc does grant single Quickcasts every 15 seconds if Conc is burned immediately upon refresh though. This makes it stronger in the sense of adding no extra delay to Conc's reuse (33-35 second) but weaker in the sense of no back-to-back Quickcast.
The side effect of bumping current ConcV to ConcIV is obviously cheaper "ConcV". People underestimate how strong it is especially for sorc, theurg, necro, mentalist, eldritch, spiritmaster.