Since the patch my NPCs in BG2EE are rebelling against my better judgement and are casting buffs and attack spells without my interaction. I have gone through the game options but I am not seeing how to stop this...anyone else having issues with their NPCs acting out with minds of their own?

Disregard: Apparently the game loaded the Party AI (a button I had never utilized...EVER) option as on. Fixed.

Noticed this. It means they attached scripts to the characters; you can select or disable these in the character screens.

You can edit each individual party member script, and have them do (or do not) as you please.

You can also write your own scripts. Of course, this does allow you to cheat (like, for example, putting ForceSpell() in the scripts), but it allows for a greater degree of AI customization than otherwise available.

It is worth noting that the enemy AI does actually cheat in this way. (Some mods that change the enemy AI, like Sword Coast Strategems, I believe, try to do away with blatant cheating in enemy AI scripts.)

Out of curiosity, what does ForceSpell() do?

ForceSpell() casts a spell, even if it's not memorized. Furthermore, the spell can't be interrupted.

There's also ReallyForceSpell() which is even more powerful. The spell is cast instantly, and the "one spell every 6 seconds" rule is ignored. It is used, for example, for enemy spell sequencers and contingencies because the game engine doesn't support the use of the actual spells by non-party members.

IESDP has documentation on the actions that can be placed in scripts:
http://gibberlings3.net/iesdp/scripting/actions/index.htm