>1.) I think bind works differently then you do. I think the
>amount of mana only increases the chance of landing the spell
>and maaaybe the duration but doesn't have any affect on
>morale(without edges) or on difficulty of a servitor to break
>it. I guess I could be wrong though.

This is correct. The only thing that extra mana impacts is the chance of a successful binding.

The only way that any of the binding spells will impact servitor morale is when certain edges are in play, and those are static bonuses that aren't dependent on whether extra mana is used or how much.