Seriously, the only way an NPC can 'hold' an item is having boxstackers in your party - they will pickup any item you pick up thats similar (ie you pick up a cargo crate, and so do they). However you cannot see it when you scan them as its a rough hack of the code to make it work.
I don't think so. Ellias would know waaay more than me lol but I seem to remember reading (or hearing? Dev meeting vid?) that eventually it will be a simple matter to give items to NPCs and the like who are in your party. I imagined this is something that may come with combat? Dunno, but I'd assume there'd be ways to equip them with armour/weapons if it's their role. Otherwise the millions of suits of armour or weapons being made for a population of 4380 sentients would be kinda silleh.