Alright so here's the deal. I see from your infraction history that you've been warned twice for general communication skills and once for being wordy. I hope receiving an actual infraction sinks this in a bit better. Truly your post has relatively decent content. You have provided a reasonable amount of support for your concern regarding mana issues. I feel like you occasionally give in to whining a bit hard (especially given that we're not remotely near CATA release), but that doesn't make your concerns entirely unfounded.
That said, no matter how good your post is if you don't post in a manner that makes reading it easy, no one will read it. Their eyes will glaze over and their head will pound furiously. I stopped reading your post twice in order to get to the bottom of it. Your lack of proper structure and capitalization detracts from whatever valid points you may have made. It says I typed this up quickly and couldn't be bothered. Given the length of this post, if you couldn't be bothered to structure it well -- why should anyone bother to read it?
Against the normal routine I will not shit heap it, you've met the content burden easily where your post (although whiny) has a point beyond the tears. My advice: When you get back work on simmering down your whining and put that extra energy into making your posts easier to read. You'll accomplish more this way. (You also won't end up banned this way).
The mana concern problem is with the costs of all our spells. I have no doubt the model will work fine for PvE. The problem is with PvP where absorbs and considerably less than 100% contact time exists. While this is the first iteration of the new talents, if there is no discussion about possible problem areas, then those areas can be overlooked and be unaddressed far into release. We don't want another season 5 where imbalances (though in s5's case it was an OP imbalance not an underpowered case) remain throughout a whole tier of content simply because no one wanted to speak up.
Ret Paladins work fine on their model because they dont constantly use alot of spells blowing lots of mana. They actively use Divine Storm (12%), Crusader Strike (5%), Judgements (5%), Cleanse (6%), and Exorcism (8%). With DS at 10 sec cd, CS at 4 and Judges at 7 in PvP gear, 1 Judgement restores their primary rotation while in melee contact to burn said rotation constantly. I'm not saying they don't use other abilities but they're not constantly spammed. If they are being kited they can use Judgement on another close target for the 25% regen without needing to turn to get in melee range with them.
A paladin doesn't need to spam cleanse on his team without needing to remove key things like CC or Immolate against destro locks and Flame Shock against Ele Shamans. I'm not saying they don't use Cleanse alot, i'm just saying they're not constantly GCD locked by constantly using it etc.
On the other hand Shamans are constantly casting. Purge is used significantly more than defensive cleanses due to the sheer amount of HOTs/Shields/status effects/etc that are used by healers. More importantly though is totem cost associated with constant movement and redeployement.
Without being hit and triggering WS procs (which because of our issues with mana, WS is a requirement to use in long games, meaning Static Shock isn't even a PvP option since we can't use LS) we run up to engage a fight, and not using Spirit Wolves, we drop a Stoneclaw totem for the initial shield (8%), a set of Grounding/Tremor/Ele Resist/Searing (22% total), Frost Shock (18% without SF), Unleashed Elements (7%), Wind Shear an incoming CC (8%), and 1 Purge for some preHOTs(14%). This totals for 74% of our mana pool for opening totems and the opening ranged snares for the start of the fight.
Even if Primal Wisdom was 100%, we'd need 15 melee attacks to regen that, and you can't really count SS and LL's attacks into that since after using both spells you'd only be up 3% (again given the 100% example). At a 2.0 swing speed after some Haste effects (which generally doesnt happen in PvP gear) it takes 16 seconds of pure unabsorbed contact time to achieve. During which time you've likely needed to purge an absorb shield, shock a couple more times to either keep them slowed and in range or for damage (though at 18% just pure damage is unlikely), wind shear another CC or a heal, and redrop a grounding, and cycle an earthbind/tremor, possibly even another searing totem under the new searing talent model. So in that 16 seconds of regen time you've added another 52% mana used, 1/3 of which you probably didnt have to use in the first place cause it hadn't regenerated by then unless you got hit by an attack and procced a WS orb.
This example isn't even counting things like Wolves (12%), Bloodlust (26%), Ghost Wolf (6%), or Maelstrom instant LB (6%) or LvB (10%), of which BL and Wolves would also generally be used at the start of a fight. This is counting BG fights too as when you die Sated goes away, so BL is going to be used often and early to win confrontations and get the 5min cd rolling etc.
Under the old model of SS regen, at 35% per hit, while I was still worried for the reasons i'll finish up with after this, it wasnt as bleak an outlook as the current Primal Wisom is (though I prefer the procs on all melee hits, 40% for a mere 5% is really low). That same 16 second example to get back the 74%, with the old Imp SS, 70% would have been regenned in 12 seconds, with another 35% coming 2 seconds later. Though hurt more by absorbs than the Primal Wisdom model, the large chunk regen sustains the burst nature of our mana usage easier than the low proc model.
To summarize, our problem is the relative cost of spells to our mana pool. Our mana works on live purely because we have the buffer zone to allow the nessecary regen through WS and SS. If we have to burn half our mana pool to get back to a target that is ok, because we had the ability to regen it when in melee combat. But with our total mana pool being reduced from the current 3x base pool to just the normal 1x base pool, then if we burn all our mana just getting back into melee, we have to rely on 40% procs to get back any mana as well as hope we're the target for WS to get mana back.
That's why i'm making a big deal out of the mana issues. If they gave us +250% mana in our specialization (or % mana from stamina/agi) then we'd be perfectly fine with the situation, nothing would be changing essentially. But with the base pool and spells costing what they do, we'll essentially always be running on near empty and relying on Water Shield mp/5 to be able to do anything. Even popping SR for a full bar wouldnt be a giant fix because instead of a full 15k bar to work with we get 5k (using 80 base numbers) which is essentially gone again in a totem relay, frost shock and 3 purges.