"a) charging a different rate for different keywords you want to hit."

What's wrong with that? Ranking for a very generic keyword such as "widget" would definitely require much more time, effort, and money than ranking for "easy blue widget".

"c) doing 'off site optimization' is not SEO, that's spam."

Where did you come to the conclusion that off-site optimization is spam? Link exchanges, directory submissions, etc, are not "spam".