If someone mind controls a 10 point character do they take 1 point of damage?
Thanks in advance.

Nope. It's only for the full 100 points that you get a click of damage. If you MC 99 points worth of characters, you do not take a click of damage. Its not until you hit the combined value of 100, then you take 1 damage (and every full 100 points after is another damage added on).

Could anyone tell me why? Don't the rules say that you are supposed to round up unless noted otherwise?

Oh, I think I figured it out. The rules say you are supposed to round up when a value is halfed (ie charge).

Right, so a 9 movement on a figure with Charge gets to move up to 5 squares (provided there is just clear terrain).