(I just remembered I logged out in moonkingear after raging in pvp x.X Oops! )
I feel your pain on not having enough haste. Having too little makes you feel inadequate and then too much drives you nuts with GCD clipping *smallrage* (which is the reasoning behind me dropping Natures Grace)
As for the glyph of nourish I believe with all Hots (regrowth, rejuv, lifebloom, wildgrowth) it will heal for 44% more.
Since you get 20% more for just having a hot on the target, then the glyph adds an additional 6% for each hot.
I personally hate rejuv blanketing.. but sadly you have to do that sometimes.. I really only blanket on fights where I know aoe is going to happen and even then you sometimes have an idea of who it will hit (melee or some wonky ranged aoe spell), but really if you only focus on 10 or 12 people thats not too bad since you won't be the only healer
and thats 10 or so people having a trickle of health refreshed.
I've found to really focus on the squishy type people.. Like Mages, priests, or that dorky Moonkin/elemental shaman since they tend to be the last people to try and do anything about their hp dipping. Rogues are kinda bad about it as well.