Gear swapping (aside from weapons) doesn't fly in combat. So swapping out that feral staff for a caster staff is fine, or a MH and OH (as long as it's not a shield) will also work. Armor is a definite no-no, not completely sure about trinkets; I'm pretty sure you can swap out trinkets in combat, most of them anyways, not sure about the ones that add armor.

I use Outfitter for solo toons. If you want a macro for a full set, it's still doable, no different than the old weapon swap macro I use on my 19 rogue, but you might be limited by the 255 character limit on standard macros.