I think the reason it moves the whole leg is because you haven't finished the foot rig. You have 2 IKs set up on each foot but they won't do you much good unless you connect them to something like a reverse foot rig. There are lots of tutes on reverse foot rigs if you look around. Once you set it up, the foot won't rotate when the rest of the leg does.
Here is a link to a rig video that I did. If you look, you will see that I rotate the pole vector and it causes the knee to move but not the foot.
Hang in there. It gets easier as you learn more :attn: