Sure can!
No you can't
Yes you can celebrate your own party without guest services.
Yes you can. I just had a party for my son in August without renting it out for their birthday package. They let us bring in our own cake and juice boxes. I ordered the food from there though.
Yes you can do by your self
I think you can still have a party there. It is moreso about renting the space to you than it is having their services. But last time I checked, the guest services are included in the booking fee but it helps to check with the operators of the facility as well
Thanks! Your answer is awaiting moderation.