[icarus]

Well I'm no expert but I'll take a stab off the top of my head:

1. No idea. That's a good one. Makes me think of Little Miss Sunshine.
2. MSG or monosodium glutamate is essentially a neurotransmitter (glutamic acid), so probably gets your taste buds firing off more readily than would otherwise occur.
3. I tend to consider something to be alive if it can make accurate copies of itself (for mitotic cells) or in union with complementary gametes (for meiotic cells), so fresh sperm cells would be alive so long as they are fresh enough to penetrate an ovum and release their haploid DNA.
4. Hiccups I believe are caused by pockets of unreleased gas buildup within the stomach that can stimulate an autonomic response. I guess if you get rid of your hiccups but you've still got something in your stomach that is allowing gas to be built up then you might still be at risk to have them return.

Do vets treat fish? Is fish treatment something that's taught in vet school?