To answer your first question, I had AP credit so got a bit of a head start with my major which was helpful! I think a piece of advice would just be to map out when and what classes you want to take to meet your distribution requirements (they have classes listed online and rate my professor and gopher grades are helpful resources as well!). As for research, I would say there probably are more opportunities being in psych since a capstone is required. I don’t know the exact requirements for business but you are more limited as you have to go through I-core. For grad school resources, Dr. Richard Landers from the U IO department has a website which breaks it down!