I played these games when they were new (without the expansions) and plan on starting a game after completing Geneforge 5.

Are AI scripts just a way to let Baldur's Gate play itself during combat? I'm curious because I'll be running this on a laptop without a mouse (keyboard & crappy touch-pad), so I'm wondering if these scripts might benefit me.

The AI scripts in Baldur's Gate are... basic at best. Not only that, if you are playing a spellcaster, or have spellcasters in your party, the scripts are the surest way of wasting valuable spells, unless you assign your spellcaster an attack only script, such as the default script. To me, leaving the fighting to AI is depriving yourself of half of the fun of the game -- micro managing your party during combat is part of what makes the game what it is. You will be pleased to know that Baldur's Gate makes this very easy by allowing pausing on triggers, set in game options: Gamepl;ay >> Auto Pause. You can choose to pause on:
Character hit
Character injured
Character death
Character attacked
Weapon unusable
Character's target destroyed
End of round
Enemy sighted

Those are just in BG1 -- there are more options in BG2.

Thanks to Tallima for confirming my scripting question and to Hickory for those combat tips. I'm not going to worry about AI scripts and will instead set up a bunch of pause parameters.