If there were any interest in allowing multiple improvements to coexist, I'd be in favour of the idea of canals, but as it is, I would not be in favour.
I am in favour of multiple improvements per tile (a mine or workshop doesn't take up the land that a farm uses!), but I've been advised that this is hard to do in CivIV - perhaps that's why there was difficulty in implementing this in C2C.
Cheers, A.
