Since your guide covers about everything I have little to add
Just one little advice for people who know nothing about bikes but are looking to buy one:

Most bike manufacturers do not actually "manufacture" bikes, they simply make a frame or even more simply buy a cheap taiwenese frame and put their name on it ... and then they fit that frame with components from other companies.
Most people look at the rear derailleur to determine the overall quality of a bike ... bike manufacturers know this and so they will mostly fit a rear deraileur that is of better quality than any of the other components of a bike. Considering that the rear deraileur is a relatively cheap component, the manufacturers are trying to fool you and by doing so they try to make more money!
Do not be fooled by bike brands that use this method.
There are serious brands outthere that will fit a whole bike with components of the same "group" and quality ... these bikes are obviously going te be a tad more expensive ... but you will at least know what you bought and you will know you can rely on it.