If an adult is takes their kid to the park must they pay to get in even if they don't ride the rides?

Yes - they could have controlled free entry of adults in such cases through bands but perhaps they don't want to lose this revenue as they know parents will come along with kids and will not have much choices.

Only children 2 and under are free. Everyone else must pay.

Yes, 3 and older.

Yup

Yea everyone and anyone must pay to just get into the park. Reguardles if they ride or not

Of course, full price

Yes full price

Sadly yes, otherwise the park wouldn't have a way of knowing who passes on the rides. The cost is more for theme park admission anyways.