Yes, if you plan on going to graduate school, absolutely.
In that case, classes in statistics + biology/neuroscience will come in handy.
If you’d rather have a job right away, you can take the “I/O Psych + some CS” route - it doesn’t prevent you from going to grad school of course.
Have you run the NPCs in #26? What are the results?
Yes you can still register for the SAT AND the ACT (with late registration), in December. Considering that you’re likely to score higher in CR and that a 1400CR+M “unlocks” LOTS more scholarships, I don’t see a downside.