One down...
N to go. Fixed the GTK PLAF problem by inadvertently opening the arduino script in Emacs (I hadn't realized it was just a shell script). Saw that it was explicitly specifying the GTK PLAF, and took that part out.
Now it's kvetching about not being able to find the preferred system font. I swear, these computers, they are never happy!
Now it's kvetching about not being able to find the preferred system font. I swear, these computers, they are never happy!