Buff Injustice

[mikebr99]

From the SRD:

To have any chance of activating a scroll spell, the caster must meet the following requirements:
• The spell must be of the correct type (arcane or divine). Arcane spellcasters cannot cast divine spells from a scroll, nor
can divine spellcasters cast arcane spells in this manner.
• The user must have the spell on his or her class list.
• The user must have the requisite ability score.
If the user meets all the requirements noted above, and her caster level is at least equal to the spell’s caster level, she can
automatically activate the spell without a check.

So, unless your DM has 'house Rule'd' this, cures aren't in the Wiz.'s spell list, so he can't use that scroll.

 

[mikebr99]

Damn you faster typers...

 

[Voadam]

As for a reason why Cat's grace is not on the cleric list, Clerics are generally tanks, paladins with better spell casting. They get d8 HD, heavy armor, and are expected to be back up main line fighters. They are basically based off of knights templar and their spells make them tougher in general. The buffs go along with their strong soak up the damage protection theme and their smite them hard theme.

Dextrous grace is a bit outside the cleric core theme while strength and con are within it.

 

[Voadam]

I'd say divination and healing are the other two big themes of the generic cleric spell list.