The various suggestions you can give Lavitz when visiting his house.
Mappi and his pals, when they face you for the first time.
I remember a very funny but optional cutscene that happens after you helped the little kid and his mother to reach the city (i don't remember the name) on the island in Illisa Bay during act two. If you visit him later in the clinic he'll tell you about his wish to become an adventurer like Dart. Depending on your answer, a funny event with Meru/Rose/Shana will happen.
Near the end of act 2, you have to look for your friends in Zior's castle. You stumble into Meru and Haschel as they're being kicked out of the kitchen, and you can have the chance of supporting their idea.
A mininto in Lohan offers to Dart a "Special Ticket". Then when Dart asks him what's the actual difference from a normal one, he realized that he has been tricked and goes apeshit.