1. Well, I would assume they aren't renting something far beyond their means, which would be akin to throwing money away on expensive car beyond one's means.
2. I didn't catch whether you are paying a lot for locomotion.
3. I suppose, but the idea is really that you have basic living expenses, and then "disposable income". Nobody who makes what I make should be buying a $40K car...
There comes a time in life where not everything needs to be an investment, unless you are just doing it to leave your kids a bigger estate. As one wise person once told me "if you don't fly business class your kids will."