With JEvents and the gold member addons you can do all of the above APART from
1. There is no way to take a fee for you when the event creator gets paid
we want to get fees about this and give the creator his money less our fees.
Paypal has an experimental tool for making split payments but this has not been implemented in RSVP Pro. You do have the option to charge event creators for creating events on your site as an alternative.
2. Slideshow would need some basic javascript/css to convert the presentation of the latest events module into a slideshow.
3. Tickets can be printed but not barcodes - I have prototype code working for barcodes/QR codes which can be printed on the tickets but this is not in the production system at present.
4. Early bird discounts is a feature which we are planning to implement - we already have support for coupons and deposits so its simply a matter of us combining the functionality.
All in all the biggest obstacle is directing payments to 2 different payees when an attendee makes a booking. There is no easy way to resolve this I'm afraid.
Geraint