The first priority should be fixing hots and dots - first tick as well as scaling. Secondly making wis more useful - and not by increasing matk with it.
Pretty much your complaint is gcd change. I hear you, it hurt my p/r bad. But. It affects all classes, so it has nothing to do with "omg they nerfed priests again".
This isn't really a thread dedicated to the new GCD. But yes they did nerf Priests again, as well as all casters. RT is a 3sec cast, now it's 4, UH was a 1 second cast, now it's 2, GH was a 3 second cast now it's 4, Heal was a 3 second cast, now it's 4, Bone Chill was an instant cast, now it's 1. It didn't change the actual cast time of the spell, but it increased the time between spells.
How do you not see that as a nerf when Priest feed back threads are filled with complaints of skills that do nothing that weren't ever addressed (cleanse, Magic Barrier, Wave Armor, Ice Fog, Blessed Spring Water, Heal......etc). Yet they nerfed almost every useful Set Skill (Holy Candle Shield, Alter of Shadoj, Frost Scars) then added a debuff to GH and called it Balancing.... ?. One of those by themselves is tolerable, but they are continuing to accumulate to the point that even the most veteran Priests have had about enough.
Not to mention the effect the GCD has on Mages DPS, as I also have a M/P alt. Priests were already the bottom of the DPS totem pole, now they just got pushed off the ladder.
If anything this GCD has created 1-2 button rotations. UH and GH will be the new rotation. If a Priest loses 2 seconds for every 2 spells then it defeats the Debuff of GH which was tolerable by itself, but then it eliminates the time for other spells to be put into rotation. As for the argument specifically to the P/S class, this made Ice Blade more of the spell of choice because no one is going to cast Rising tide, and BC make such a minute difference it's not worth adding to the rotation for the eaxtra 1 second cool down. So now even more are going to start crying for even more nerfs to that class.
The ticks and DoT's won't bring back or save Priests from leaving the game, they are a minimal effect.
Adding Matk to Wisdom benefits most of the Priests out there by addressing their lack of damage ability. Making it have equal benefits to ALL casters will address the issue of Mages avoiding the stat and complaining in PVP when they have no mdef. If they made Wisdom primarily a Heal increasing stat then that will only create another nerf down the road for any healer combo. I can hear the QQ about that already if a Wisdom stacking Priest can increase their heals substantially by stacking Wisdom (heals out heal damage taken), and that will lead to a nerf of HPB on gear or on the skills themselves. If they were to increase the heal effect of Wisdom it would lead to a substantial nerf of something else.