Actually the 8's aren't the same speed as the same as the 3's... I know this because I use the same sprite for charge weapon and charge skill, both set to 8's, and the weapon animates slowly enough, but the skill animates as with the default frame setup.. I've cranked the frame's to 20,20,20,20 and i get the same as before..
I know the player gets the penalty because he's immobile while the ally is casting. Once cast the ally moves normally and the char I'm controlling is locked in place for the penalty time set. The other case is when the enemy uses the skill and all the battlers stop moving during the spell. I don't think it's lag because I'm running a quad core and it's a smaller test map I'm experimenting on.