Reason 3 is pretty interesting. I'm big on the science of vestigial quirks.
sudden temperature change that's following a disturbance in the nerve pathway
Probably closest to me - Spice makes me hiccup. But then I'm not sure that's actual temperature or the perception of temperature. Even the mildest spice will make me hiccup, one that I could otherwise drink like syrup.
It's a life curse I have to live with. Sigh.
Very interesting - I haven't met anyone who gets hiccups when eating spicy food before. It makes total sense due to the "heat", just like you said