Trinity can let you program a myriad of bars, with multiple states per bar, like an in combat bar and an out of combat bar for instance (to keep your buffs n stuff)

What I do, is simply put most of my tanking spells on a separate bar and just click cast em, while I use the keybinds for the slaves. I have a few overlapping spells in my main actionbar (consecrate tied to holy nova/arcane explosion/hellfire for my AoE farming, but for the most part, my paladin's main action bar is blank. One thing you could do is just set up trinity for multiboxing, and just deactivate it for raiding solo. Or just use action bar 1 for solo and action bar 2 for boxing.