Under payment information you are asking for a first and last name. Payments are being directly deposited into a reunion checking account, not a specific person. Is this information needed in my case? It indicates it is required?

The field is required, no matter what.

So what you could do is say the first name is "Class of" and the last name is "1970 Reunion".

It should be the name on the account when you created the account, whatever that name is.