1) Oil must be added to pasta being boiled in water to prevent sticking
This one is definitely false and in fact will disrupt your meal. The oil coating will prevent sauce sticking to the pasta when you want to eat it. The right way to prevent sticking is to stir the pasta.
2) Rinsing the pasta once it's sooked is needed to remove starchy buildup
Once again washing off the starchy residue will prevent your sauce sticking to the pasta. Only wash the pasta is it's going to be used in a salad.
3) The flavour of pasta can be improved by ading salt to the water.
Salt will improve the flavour of the pasta, a good amount is required as most of it will be washed off when the pasta is drained. However it also has other effects - adding salt will increase the boiling point of the water so the pasta will be subjected to higher temperatures when the water boils. Make sure to check the pasta regularly, your usual cooking times might be thrown off.
4) Mushrooms will absorb water used to rinse them so they shouldn't be washed.
Mushroom are porous, but it takes a long time for them to absorb any meaningful amount of liquid. Feel free to rinse them, you could end up with something much worse in your meal if you don't!
5) Dry spices never go bad. True or False?
Dried herbs and spices last forever
This is both true an false. Dry spices won't go bad but their potency is reduced quite quickly if they're not used. A good general guideline is that if they're over six months old they're probably not worth keeping any more. Refrigerating them will actually preserve them more effectively, but if you do this try to minimise the humidity they're exposed to.
6) Alcohol burns off in the cooking process, so the final meal is alcohol free.
This is generally false. A dish cooked for a few hours might lose almost all it's alcohol content, but the more usual methods associated with alcohol, say saut? of flamb? will only get rid of about 5)% of the total.
7) Baking soda and powder will stay good forever.
This is both true and false, baking soda will indeed stay fresh effectively forever, however baking powder will not. Once it's exposed to the air baking powder starts to lose it's potency. Unlike spices it shouldn't be stored in the fridge, instead make sure it's not exposed to much moisture.
8) Fried potatoes can be made crispier by soaking them in salt water beforehand.
This one is true - soaking the raw potato before cooking will help make them crispier. Careful with the salt concentrations though, too much is unhealthy!
9) Grilled meat should only be flipped once to ensure proper sealing?
This is false, flipping repeatedly ensure even cooking throughout, much more so than just flipping it once. It cooks faster and will be browned an sealed just as well as meat cooked multiple times.
10) Beans will be toughened by being salted before cooking.
Completely false, in fact this has the opposite effect. The salt will make the skin tender, and the beans come out creamier. The softening means they're less likely to violently explode when being cooked so overall pre-soaking the beans before cooking is an excellent thing to do.