1) Red wine with meat, white wine with fish
Uh, no...While this generalisation has been around since Adam was a lad, there is pretty much no wrong combination. It's personal choice. If you like drinking a great big, beefy syrah with a gurnard fillet, do so. New World liquor merchandise manager Brendon Lawry maybe put it best when he said: "That's the whole thing about wine - you can't tell anyone they're wrong."
If you are undecided, it's best to look at the flavours involved. Grunty food generally needs grunty wine and vice versa. So you might not want to overpower delicate steamed fish with a muscular red. On the other hand, a hearty, tomato-based fish stew goes well with red.
2) Red wine causes more headaches because it has more sulphites
Red wines actually have fewer sulphites (used for preservation in many wines) than whites. In any case, sulphites do not cause headaches. Hangovers do, caused by dehydration from alcohol - though asthmatics can suffer an allergic reaction from sulphites.
3) Wine tastes better with age
Most whites are made for immediate consumption. Most reds are made for consumption within five years of release and many are best drunk before then. Many wines go from youth to old age without ever achieving the fabled "sweet spot" where the wine is supposed to taste its absolute best. There are exceptions, of course, like grand cru Bordeaux, where, depending on vintages and skill, they can age for many years - but those wines are a tiny percentage of the world crop.
4) Open a bottle to "let it breathe"
Well, yes, do. But if you really want to aerate your wine and bring out all its smoothness and velvetiness, either pour it into a glass and leave it or decant it. Leaving it in the bottle does little because the bottleneck doesn't allow much aeration.