I'll stab at the first question, having little experience to back up my opinions. <img src="/forum/images/icons/smile.gif" alt="" />
Yes and no. Remember that your looking at 8 different mobility options so the posture is less important than where you are going. If you pass forward to the right side you'll naturally fill the initial front leg more and then rebalance.
I think that 50/50 split is what gives you the full 8 direction (anyone else note how the Segno relates to the old "Chaos" symbol

) ability. Like a guard most of the non-50/50 seems to be transitional and dynamic.