Is it possible for events to have their own Paypal account or is it one Paypal account for the complete extension? For example if the website has several events organised by different people can it be the organisers Paypal account or must it be just one default account?
Each event can have it own PayPal account to receive payment if needed. You can enter the PayPal account which you want to receive payment for the event on Advanced Settings tab from add/edit event screen