This said i was tryin to take note of any possible thing that might be changed to make disc priest a solid class once again. I devided my ideas in different categories. Here is what i think, hopin you find it intersting and can give your contribution for it:
After the rapture hot fix and with the upcoming buff on mindbender (1.5 up from 1.3) i honestly don't have any problem managing my mana in arena matches. Notice i stack spirit on blue slot, have spirit/resi on yellow, int/pvp power on red and using int+2% mana as meta. So far i got 9k spirit (i'm BS and JC) plus the proc from the darkmoon trinket (aka 3k spirit with 45 icd). Using mind bender pretty much on cd unless settin up a kill, makes me perfectly fine on mana. Not even using hymn anymore. The problem with this is gear setup is you get really lower pvp power: i'm runnin with current 19% pvp power (yet to get pvp t1). Should be able to drop some spirit gems as soon as gear lvl will be higher and focus bit more on pvp power. I honestly don't think mana on priest needs to be buffed, it's other healers regen that needs to be nerfed (see resto druids or shammies).
Another thing to do should be the revert of inner focus: buff crit and put it back to mana free cost of next spell casted. Also lowering the cd of P.I. would be a good thing, say 1.5 min. but this last one can be discussed better.
SURVIVABILITY AND CC
Here is the worst part. Being a cloth user with very few cds is disgusting: atm pretty much any melee on cds can destroy you, like.. litteraly blow you up. Focused will is a good buff but it won't be enough to grant priests a way out. What can be done ?
1) PoM needs a consistant buff: let's face it, every class but priest got really good instant heals. Priest got nothing. With cds, shammy pala or druid can pick up a target from 10% hp up to full. priest still needs to put off at least 2 casts. This has to be changed. Not askin for a priest version of NS but they should at least considering buffing PoM and renew. Renew ticks for 6k in arena with 17k spell power. that's ridicolous : it's 2x what it did in cata but hp pools are about the double. Almost useless.
2) The change of glyph system should help on this. Having desperation, inner focus and sw:d all base line for disc (for shadow the glyph of sw:d does make sense) would be just fair and won't affect pve at all since those are not chosen for pve anyway. Think of Shammies having aura mastery (lol) or druid able to cast barkskin under ANY condition or iron bark on a lol30 secs cd (if i'm not mistaken). This would allow the disc priest to choose stuff like Glyph of PW:S (used to a must in cata) for extra instant heals. Just fix it so that it doesn't convert absorption but ADD heals to the normal effect.
3) I don't think set bonus needs to change. you have fade with phantas if you wanna run free and tbh the set bonus atm is rather strong.
4) PW:S needs to be undispellable and to balance that u can nerf strenght of soul to 1 sec down from 2. either that or reove glyph of purge. having a retard chasing you spammin purge while warrior is litterally but rapin you ain't fun nor skillful. Either this or make Spirit shell undispellable.
5) Reduce the cd of PS and PW:B to 2 mins
6) You could make Void Tendrils a base line ability with a longer cd. After all all items have some kinda snare/root. Keep in mind priest also doesn't have interrupts what so ever, this would be a good compensation considering we even lost MC and MB.
7)Psyfiend. Increase it's cd to 1 min up from 45 secs, but make it horrify ppl (still dispellable ofc) for half the time. So instead of 8-4-2 make it 4-2-1 but with no dr with psychic scream. Even with a glyph.
8) Divine Aegis : needs to be changed entirely. !@#$ the buff to 50% of crit heals: if anything this will be either purged or will just get games down to rng. Now, considering we run usually with somewhat like 6-7% crit, i'd say it's pretty ridicolous. Just make it create an absorbtion of a certain lower ammount (say 20%) ) and work on everyheal. This way you don't even need to buff other heals which with 4 set bonus are quite fine if you ask me. Maybe just buff penance a little bit
9) throwin it out there: how about bringing back divine hymn ? it was honestly a great spell. My dream is to have the wotlk prechange version of it.. the one that other than improuving heals on targets was stunnin enemies. Loved it.
Priest has always been chosen for its dps output. Old wotlk rmp was considered to be a 3dps comp. Now, our dmg atm is %^-*in terrible and I guess it's because of attonement and how it affects pve. No need to change it all around tho so u can fix this without rapin pve. How ? simple: if you fix main glyph slots (as i said on survivability part) you have free spots in which you can take glyph of holy fire and glyph of smite. They significantly increase dmg output and game would stay the same. Nobody takes desperation innerfocus or sw:d for pve anyway.
Once upon a time priest was the best dispeller in game. It could dispell twice off/def. Slowly dispel magic has become everyone's ability with disturbing exceptions like shammies being able to heal while dispel, dispel all curse and magic + 2x dispel offencively while glyphin for it. This has to be changed. Druid and Shammy have a great plus cause being able to dispell curses. How do we give priest something that makes it special without destroyin pve ? Ideas:
1) As Disc, your Purify (def dispel) cd is reduced to 5 secs.
2) As Disc, your MD cd is redused to 8 secs down from 13. Keep in mind before cryin that MD has an insane mana cost (40k) so you can't really spam it. Glyph for faster cast will still be needed but under the condition that the 3 we mentioned already will become base lines for disc.
a good alternative for the point 1 would be having Purify on 2 stacks so that you need to cast it twice before it triggers the cd. Pretty much like warrior charge or freedom talented or Roll from monks. So basically u can stack 2 x dispel and use em in a row. Just an idea, feel free to like it or dislike it.
With this changes priest will make a real come back on the ladders and, overall, on game since nobody is actually playin it apart from some insane multirank1 makin rmp still work. Any suggestion/idea/positive criticism is very welcome.