There's friction there, and since family is family, the friction has a personal intensity to it, even though it's tempered by love. However, IIRC, Quark and Nog don't actually interact that much in Avatar. The idea of Jake soaking up Quark's craftiness really appealed to me. They're new acquainatances. And before you ask, no I won't say which one.
Hope springs eternal.
All quotes, unless attributed otherwise, are from Marco Palmieri, editor of the new DS9 series.