RE: Balance vs Non-Balance Charging
It is not necessary to balance charge the pack. Normally it will be perfectly balanced if it started out that way before use. (try it once and see)
Your example is a bad difference , but none the less you are correct. It would be a bad idea to balance the pack before charging (if it started out perfectly balanced before use)
Here's an example that may illustrate that capacity,IR,voltage, ect has nothing to do with cell balance.
Let's build a pack with grossly differing cells
a old 1300
a new 1500
a new 5000
a cheap ebay 3900
a High IR 1200
an unknown cell
This pack is perfectly balanced at the full mark can be used normally (down to the lowest capacity cell's minimum) within tolerances. It will be severly imbalanced when 1000 mah has been used. It can then be recharged thru the discharge lead without balancing and will be again in perfect balance. This can be done again and again. I am convinced that varying rates of self-discharge and Damage are the two things that "throw a pack's balance off"