Hmmm -- I know I use a lot of vinegar for different things, some that you've mentioned. Also, for general bathtub drain maintenance -- throw some baking soda down the drain, pour in some vinegar, rinse with water after a few minutes -- won't work on a solid clog, but if you do it about once a month, you won't get clogs.
A bit of vinegar in the water used for boiling eggs will prevent any mineral stains on the metal pot. I've heard that it also stops that greenish coating on the hard-boiled yolk, too, but I'm not so sure about that.
For that matter, it's great for dissolving the scale (water mineral build up) in any appliance that uses tap water -- iron, humidifier, etc.
Probably the most unorthodox: My skin type is a little oily, so in the warm weather, I use unpasteurized organic cider vinegar instead of moisturizer, after washing my face at night. Must be unpasteurized, not the usual stuff. It balances out the alkalinity that causes oiliness, I guess. My skin feels great and the smell doesn't last too long.

Got that tip from an organics magazine long ago, and it really does work well. (Although my husband used to get cravings for English-style fish & chips at bedtime.)
I'll have to try the rinse cycle thing.