DSF

I got some line art that is CU licensed and has conditions with it like no mass production, line art must be coloured before sale and artist must be credited etc.
So I set about colouring and shading, once I was done I hid the layer with the line art on and I think with a few touch ups and the addition of eyes and a mouth it would look pretty good without the line art.

So does anybody have an idea of where I'd stand if I used the colouring without the line art and if it would be bound by the conditions that came with the line art?

You needed the original line drawing to create your artwork so yes, legally, you are bound by original terms and copyright would remain with original artist. Forget the 10-30% change rule, that's a myth.

It depends how close it is to the original, but you are most likely bound by the TOS.