Shattered Kingdoms

I tried searching for this but I couldn't find anything, but does mood affect spells at all? Does it affect scribing or recharging?

Defensive will slow down your spellcasting. Not sure about impact, if any, on scribing or recharging - I'd leans towards no impact.

Any reason why you would want to slow down your casting? I am just trying to think of any reason to do that?

No, the casting speed penalty is just to prevent magic users from always being mood defensive as far as I know.

Slowing down your casting speed is a drawback. You don't want it, but sometimes you deal with it to get the combat benefits of being defensive.

For confirmation, do the damage dealt multipliers of aggressive stance apply to spell damage?

Nay.

Lets say an archer comes to town and starts pelting you with arrows. Defensive stance (especially when wielding a shield) greatly reduces the damage taken from ranged combat, so it does have its benefits.