It could easily be that he's bored. Sometimes - and I don't know if you want to consider this - but sometimes that is solved with another cat. The problem is that it doesn't always solve it, and unlike with dogs, there is no guarantee that cats will get along, and then you've got two cats fighting over territory. But it's something to consider.... telling a shelter/rescue that you need a kitty that likes cats with a lot of energy...
But being a teen, I would guess that it sounds like he's bored.
Re: food aggression - does he free feed? If not - have you tried it? Does he overeat?
Sometimes for biters, a solution that has worked where nothing else has - is biting back. Of course, this could result in an attacked face. But some on here, at their wit's end, have bitten their cat at the back of the neck. Obviously not hard enough to injur the cat - but hard enough to make the point.
Have you tried yelling "OW!" and acting hurt, pretend crying (or real crying) and then talking to him calmly? I believe cats understand what we say if we say it right. We talk to ours all the time. Have you tried simply talking to him? Explaining how much it hurts and that it is not acceptable or OK?
Have you tried giving him devoted play time - 15-20 minutes at a time, several times a day with interactive wand toys?
Rather than the time-out - have you tried redirecting him to what is OK? Do you provide positive reinforcement every time you see him doing something right or playing with something that is OK to play with? Cats learn best from positive reinforcement. You say you're good with training dogs... cats operate completely differently than dogs.
Looking a cat directly in the eyes is not a sign of dominance - it's a sign of aggression. If you've been looking at your kitty directly in the eyes, try not doing that. Try looking at his forehead or over the top of his head instead. With dogs, it's palm out - when you reach toward a cat, this again is a sign of aggression. Reach out palm down. And unlike dogs, cats do NOT care about making you happy (at least genetically). They're not pack animals, and are totally opportunistic. Thus in "training" them, "punishment" doesn't work like it would with a dog or child - because it's just not "discipline" - it's something negative they now associate with you.
Positive reinforcement when appropriate (as frequently as possible), redirection to what is OK, or depriving them of something they like (the time out) work far better. I know the time-out hasn't been working - but have you worked with positive reinforcement, and redirection?
Cat attacks. "OW!" Short, sharp puff of air in face, firm "No," then redirect to something OK to attack. Perhaps get a bunch of second-hand stuffed animals to leave around so there's an easy one handy to grab to give him. If he attacks it, say "WHAT A GOOD
BOY!Or perhaps, like with kitties that are teething, buy a box of bendy straws, and scatter them everywhere. When he attacks, do all of the above but redirect to the bendy straw.
When he's not doing things right, redirect him to what is ok, tell him how good he is - and if he doesn't redirect, give him the time out. But explain to him why he's getting the time out. When you let him back out - do it without saying anything, without looking at him. Just open the door and walk away. Ignore him.
When you play with him during interactive play time - constantly tell him how good he is, what a good kitty! And finish play sessions with treats since he's so food motivated. But reward him a lot for appropriate behavior.
Does he have a lot of stimulating toys? Not just furry mice or balls with bells in them - stuff that interacts with him. Turbo scratcher? The box with lots of holes in it that you put toys into that he has to try to get out?
The best toys for human - cat interaction are Da Bird and the Cat Charmer. This page, in fact, has all great cat toys - both for human-cat interaction and cat-alone ineraction with toy. http://catdancer.com/products.htm
If you want to consider the cat dancer, I'd go for the compleat - the one with the stick-on so you can stick it somewhere and kitty can make it dance and chase it around himself.
Does he have any vertical space? Any cat trees? Anywhere to run/jump up and down? Windowsill seats? We put out lots of bird feeders - we use the kind that stick on the window, and squirrels are fabulous entertainment (the birds are as well, of course). But it's like Cat TV. In fact - having 2 or 3 cat trees right next to each other in front of a window is great for cats.
But trying Feliway - if you haven't yet - can't hurt. Also, if it's an issue of stress-acting out, rather than boredom... you might want to consider harp music as well.
But remember - positive reinforcement or denial of something he wants. If you haven't tried free-feeding, I'd give it a shot. He may overeat at first - but then calm down when he realizes he'll have access to it all the time. And being a cat, you can put his food up somewhere so the dog doesn't eat it.