Are there any traits, feats or other abilities that would let a pure-classed character qualify as a different class for the purpose of activating spell trigger items such as wands? Something outside of multiclassing or Use Magic Device.
I'm trying to see if there's something similar to the 3.5e version of the magic domain power that let you count as a wizard for the purpose of activating scrolls, wands and other spell completion and spell trigger items.
Alchemists can use the spell knowledge discovery to add a single sorc/wiz spell to their effective spell list for activating spell completion/trigger items.
There's a few rogue talents which operate similarly. Besides rogues there's other classes which can get rogue talents, e.g. archaeologist bard.
Feats like sahir-afiyun, fey spell lore, expanded spell kenning, fey spell versatility, unsanctioned knowledge etc. can add spells to your spell list.
The paragon surge spell can give you a feat temporarily, including extra discovery, extra rogue talent & the feats named above.
Expanded Spell Kenning gives you more flexibility in terms of spells that you can cast with your own spell slots but is of no help at all in casting spells not on your original class list with wands or other spell trigger items.