J.M.
This happened to my sister when she was a kid. Turns out that she has esophogeal reflux (I think) and that it causes the sensation of choking sometimes while eating. It's nothing that you would be able to see - they have to do a scope to check it out.
And, not to be mean, I think that punishing a kid for not eating is a little extreme. It's one thing to send him away from the table if he's screaming and yelling (that's the rule in our house) but to take away all of his stuff when he genuinely seems scared of choking feels a little oppressive.
If you don't have insurance, see if there's a clinic that you can take him to. Document when he's having this choking sensation to see if there's some sort of pattern (with my sister it was acidic food like tomatoes). Finally, if he doesn't want to eat, don't make him - offer him nutritious liquids. If he's really fine, he'll give in when he's hungry. If he really has a problem, you'll know it because he'll start losing weight - at which point you need to get him into the doctor ASAP.
good luck.