LaTeX: typesetting chapter and section number in margin

Answer 1

Try using the memoir document class. That has a ton of options for doing exactly this kind of thing, and it's much neater...

There's a hangnum style and for sections, there's a \hangsecnum option, but that only puts the number in the margin: it doesn't make it bigger. Memoir is also fabulously documented. So I expect all everything you need will be there. The code for hangnum is on p.88 of the fantastic memoir manual. So from there and from later examples you should get all the pointers you need to get what you want...