As for "sketch", it's just a word. I have my degree in Computer Science, I've spent 16 years earning my way by programming, I hate to think how many lines of code I've written, many bajillions I'm sure, if somebody wants to call their program a "sketch", fine by me.
Frankly it's not that far from the truth in the Arduino IDE considering that it what you write will be augmented considerably by the pre-processor - your sketch gets fleshed out.
There is however one hideous error that I have seen new Arduinites make and needs to be stomped out the second you see it, calling a function a "void", it's understandable why they make that error, because all they have seen is void returning functions, but I've even seen it in a couple of things aimed at beginners, saying things like "make a new void [....]", or "see in the void [....]".