Apple Logic Pro /LogicExpress Discussion

I am new to this stuff...

I am having some issues with my Edirol FA101 in terms of controlling
the volume and the relative mix of inputs and outputs. I have put
another post out there to see if anyone can help. I have a thought
that might get round my problems, but it depends on using a USB
interface (I have a spare M-Audio mobile-pre) for output and using the
Edirol just to get the multiple inputs. 

Is this a feasible idea? 

Thanks
Mike