This took a while to get perfected, but very pleased with the result, my Priest is very new and only level 36 so it’s obviously missing significant spells/abilities, but has proven to be exceptional for leveling and keeping some extremely bad groups alive 
1st one is a very simple Mouseover to Shield and Heal whoever your mouse is hovering over, be warned you need to watch where your cursor is:
Sequences['Disc_MO'] = {
specID = 256,
author = "Kytie",
helpTxt = "Talents 2",
'/cast [target=mouseover,help,nodead] Power Word: Shield',
"/castsequence [target=mouseover,help,nodead] reset=combat Shadow Mend, Plea, Plea, Plea",
}
Now this is what i call a DPS macro, but the great thing is it’ll shield via Mouseover, making Atonement healing MUCH easier as you don’t even need to press a 2nd macro, just move the mouse to your shield target when needed. Much like my Lock Macro it’s designed for Movement with Penance (if not on CD) + SW:Pain being cast when moving, when you stop moving it’ll add in Smite’s:
Sequences['Disc_DPS'] = {
specID = 256,
author = "Kytie",
helpTxt = "Talents 2",
PreMacro = [[
/cast [target=mouseover,help,nodead] Power Word: Shield
/targetenemy [noharm][dead]
]],
"/castsequence [nochanneling] reset=target Penance",
"/castsequence [nochanneling] reset=target Shadow Word: Pain, Smite, Smite, Smite, Smite",
PostMacro = [[
]],
}