This is a long shot and kind of vague, but is it...

LOOSE / LOSE?

There is

loose money,

you can

lose a fight

and it also rhymes :)

This is a long shot and kind of vague, but is it...

LOOSE / LOSE?

Money earned that you can't use:

"loose money"

If you

lose a fight

you'll have a bruise.

I think the "Say it long or keep your shoes" has something to do with

your shoelaces being loosely tied

and the last verse I pretty much based on rhyme :)