My first thougth was: "The will rename the new expansion to Clutterclysm!"
But yeah get rid off SpartanUI, it's way to huge.
You can also mess around with the ingame scaling or use "/run SetCVar('uiScale', 768 / ) " to get some more room.
CowTip is nice but it's so much info that you probably don't need, shown in a very space consuming way. I would suggest TipTac as an alternative. You still have the information but not everything in a single line.
If you don't like to play around in lua, pitbull or shadowedUF is probably the best way to some slim UFs. You won't need much information on them too but mana bars are important.
Omen and Recount can be de-uglyfied in their options and placed near some chat.
I don't have a pally so I can't suggest much but I don't think that you need all your seals, judgements and blessings on those bars (doesn't pallypower support clicking?).
I would disable all those minimap buttons, too. You can access most options through slash comands if you need them but I think you don't need the decursive/ bartender/gatherer/enchantrix config that often. You can also use another minimap addon to remove the minimap clutter, I use pMinimap at the moment.
I try to put all those ablilities that I need into two bars because it's hard to find a place for 4-5 bars that are filled with stuff you don't need all the time.