Luna Bella wrote:... It's a food territorial thing in his crazed little bird brain

...
My male pionus was this way too. Pi are very scrappy birds in the wild, fighting for nesting space, not social in the way we usually consider 'tiels. I worked around him too, deciding early in his life that he was too independent to be won over by bonds of affection. He would even lash out at his devoted wife to the point that I considered her a potential victim of battering, so I kept a VERY close eye on them. I've not, personally, seen this behavior in 'tiels, but b/c mine are mostly former untamed breeders, I seldom put my hands on them. Some love landing on me, but even they are wary of my hands. Seems odd to my human brain, but clearly makes great sense to them.
If your boy were an Amazon or macaw, his size and damage potential would be too great to ignore, but I would continue to "work around" a 'tiel. Just my personal way of letting a bird be a bird. And I'm certainly not meaning I'd ignore him. I'd just let his moods call my shots.