Focus on Crit rather than Mastery in 10man. Spirit, get as much as you feel comfortable with. At least 10k, though. (For this tier)
As for WeakAuras, I started out using a ton of them to track Grace, cooldowns, Evangelism, etc. Basically, just had icons of the spells show on my screen whenever they were off CD. I found that I had no need for all of that once I had actually played my Disc for a little while. Nowadays I just have a texture + sound pop up whenever Mindbender is available and I'm below (I think) 80% mana. I also have huge icons pop up at the top of my screen when I don't have some version of Fort up and don't have Inner Will/Fire on, because I suck at remembering those.
Here's the WeakAuras string for the Mindbender thing:
Macros, here's a few examples of what I personally use. I'm not saying they're the best, I'm no macro wiz, but here you go:
(Casts PoM on your mouseover if you have one, on your target if you don't have a mouseover and your target is friendly, on yourself if you have neither a mouseover or a friendly target. Also uses any on use trinkets you may have. You can replace Prayer of Mending with any other spell to get the same functionality.
/cast [target=mouseover,help] Prayer of Mending; [help] Prayer of Mending; Prayer of Mending
This one does the same as the above, except if I hold alt, it will instead cast Smite. First trying for an enemy target of my mouseover, next for an enemy mouseover, next for an enemy target of my target, next simply for an enemy target. I have similar macros set up for Holy Fire, Shadow Word: Pain and Penance as well, allowing me to keep the tank (Or another raid member) targeted and still Atonement heal.
/cast [mod:alt, @mouseovertarget, harm] [mod:alt, @mouseover, harm] [mod:alt, @targettarget, harm] [mod:alt, harm] Smite
/cast [target=mouseover,help] Heal; [help] Heal; Heal
I chuck in /cast Archangel and /cast Inner Focus into my Prayer of Healing Macro and that usually takes care of that. Not 100% optimal, but 100% easier.