Bill Wallace was originally a wrestler, then a Judoka. He busted up his right leg in Judo - which is why he only kicked with the left leg. And he only threw three kicks. Side, hook and round. That's it, that's the list. I'll be damned if anyone could stop those three, though.
P.S about Wallace - in his very last ring fight before retirement, he threw a spin kick with his right leg (towards the end of the fight) - just for the hell of it. We all cheered, he smiled.
As for either side forward - most folks use both sides. But I have yet to meet anyone in a fighting art, ANY fighting art, that is equal on both sides. Not one single person.