To me, all except 7 are relevant, though their individual relevance can vary from barely to very much. Frankly I don't understand 7
, so I cannot tell if it is relevant.
My simple and straight forward answer is that I find this forum friendly and so I visit it to see how other members save fuel. I do not hypermile myself but it is good to know what other people do/can do to save fuel.
Nevertheless, I drive with fuel economy in mind and visiting this forum helps. I think saving fuel is at least as addictive as driving spiritedly
.