I say you can roll need on companion gear if nobody else wants it on their character. For instance, heavy armor in a group of characters that can only wear light and medium? Sure, go ahead and roll need on that for your companion. Have a trooper/BH that rolls need? **** no, you roll need on that you run the risk of winning it for something that you, quite frankly, should only be using when you absolutely can't find other people to play with and being kicked from my group. That's my take on it.
Need rolling for companions when all others greed/pass = OK
Need rolling against someone whose character actually needs it = NO
Need rolling on everything when you clearly don't need it = kick
Greed rolling on everything = fine, you're just a greedy goblin. I'm cool with that.