This is a very valid concern, that apparently I completed neglected when designing. Mana would regen passively. How much I am not sure. I would say something along the lines of 10s with no actions would result in a full mana bar out of combat, inside combat I think it'd need to be slower or non-existent. The downside to this is it would slow your pace if you felt compelled to stop and wait after each mob pull. Ideally with TV and SoW that wouldn't be a terribly large issue. Definitely a valid issue though, nice catch.
You would start a fight with whatever resource you currently have, be it 100% mana, 50% or even 0%. Alternatively we could develop a reverse victory rush mechanic where upon dealing a killing blow your next attack (or just like CS, etc.) costs no mana and regenerates 100% mana. I'm not terribly keen on that idea though. I'm not sure how that would interact in an add fight though in raids. Might have to prevent that from existing. Another alternative could be a attaching a mana regeneration value to Blazing Light instead of a cost after a killing blow. That'd solve the problem of questing, have some value in PvP, and be a rarely if ever used raiding tool.
This is a fair analysis from a PvP perspective. I'm not sold that we'd be nearly as kiteable live with several mobility options in talents coupled with several offensive snare/slow/stun mechanics, but even still that would be viable counterplay. If that's to be Ret's weakness in that match-up (remember not balanced around 1v1) that to me is fine.
Not a terrible suggestion from a reduced effectiveness standpoint. I don't like the idea of charges though, That seems to suffer from the live WoG issue where it has a cost, and a cooldown associated to a healing spell. Having both a cost, charge and cooldown seems clunky. The main difference between my heal and live is that instead of casting 5 FoLs, you can cast 1 spell, to do the same healing that 2-3 of those could do, at a fairly large detriment to your resource, not your time.
Ok, so you don't like it because it has too many baseline abilities. How many is too many? Which do you think are necessary and why? What would you cut and why?
No Holy Power? So you like combo points? What about Holy Power do you find fun or engaging?
Mana usage is a vague statement. It doesn't tell me anything. What about mana usage for a magic wielding warrior do you not like? Is it the thematics or mechanics that you're averse too?
How did you derive at zero steps forward and three steps back? Which mechanics are bad and why? What would be a change that could move the spec forward? You are saying that there isn't a single good idea in this entire build?
Again, remember this was designed back in January. Almost a year ago. try to frame your response as if you were responding then. If I were to redesign this now it'd be a complete rework.