The following options cannot be disabled, even when the boxes are unchecked or playing on expert mode.
-Area of Effect Highlighting
-Show Companion Relationship Info
The AoE circle for spells is always shown. Relationship info is still shown on the character sheet and after selecting conversation options that affect relationships. E.g. when saying something funny, the "lighthearted" indicator will be shown next to Edér and Xoti's reactions to the conversation.