Can I still manage my event if I cancel my membership?
Yes, canceling your membership will not affect any current events in your account. Your guests will still be able to RSVP, you will still be able to continue planning and managing your event using the Standard (free) Punchbowl account.
One thing to note is that a free account has a limit of 100 recipients per invitation. If you had more than 100 people on your guest list before you canceled your account, you would not be able to invite addition guests.