You can definitely just omit coffee from chocolate-based recipes. I don't like the taste of coffee and frequently do this. If it's 2 tablespoons or less, I just leave it out. If it's more than that, I'll try to find another recipe that doesn't use coffee, or might replace it with cocoa powder. Most recipes I have just use a small amount of espresso powder, and none has ever suffered from just leaving it out.

In my experience, parchment paper or a silicon mat are preferable to wax paper. Depending on conditions, wax paper can sometimes still stick. I highly recommend the parchment paper route.

All correct, although from personal experience I can say that pulling small amounts (a pound or less) of hot taffy at home is not that strenuous. Taffy hooks and machines are better for larger batches.

I can confirm this. I use this technique frequently and have never noticed any problematic egg texture. I will say that separating eggs is more difficult when they are room temperature, so it you need to separate the eggs, I do recommend doing that while they are cold. You can make a little water bath with hot water around whatever dish you separated the eggs into if you want to warm them up quickly after separating.

That's right! Fudge, fondant, maple creams, Aunt Bill's Brown candy - these all use the same strategy of creating a supersaturated sugar solution, then agitating it to create microcrystals. Delicious, delicious microcrystals.

Maple syrup at room temperature is a regular solution. It has a regular amount of dissolved sugar. For example, it may have 50 grams of sugar dissolved in every 100 grams of water. When you heat it, some of that water evaporates. Say you evaporate out 30 grams of water by heating. You now have a ratio of 50 grams of dissolved sugar for every 70 grams of water. You've increased the ratio of dissolved sugar to water and when the solution cools down it will now be super-saturated. See also: link