Work ethic probably outweighs everything else over time. Getting something done that is sub-optimal still beats a great design that's never implemented.
"Don't waste time" -- good luck with that one! Might as well rewrite this how-to as "just do it, you lazy bums!"
"How to make a million dollars: 1. Work diligently at something that will make you a million dollars. 2. Just buy a winning lottery ticket."
Admonishments regarding discipline are fairly useless without instruction on how to go about doing so, which is obviously needed if you have to advise someone to be disciplined -- if they already knew how to do it they wouldn't need your how-to.
A nonissue. Some gain weight as dust settles somewhere on the housing; others lose weight due to erosion during handling. It's a grain of salt difference.
Additionally, weight differs slightly depending where on the planet you are as Earth bulges around the equator some 80 miles more than around the poles. The farther you are from the center, the more the pull of gravity diminishes. Increasing elevation also has this effect.