Hello! See answers below...
1. Set the Paypal email address (or other payment processor details) per event (i.e. to go to the individual organizer)?
Yes, DT Register has a global set of payment options, but you can set unique payment settings per event... including different payment gateway accounts, different currencies, etc.
2. Allow the person buying multiple tickets to enter only their details to secure the registration (i.e. not have to fill out details of the other ticket holders)?
Currently a group registration requires filling info for each member/ticket. Hopefully this will be changed here pretty soon. For now, you can make a custom field for a user to select how many tickets they want, and assign price values to each option. That will work just fine... only issue is that it won't count towards the event capacity. That may or may not be an issue for you.
3. Generate unique e-tickets/receipts that can be checked at the venue before admission.
Each registration record is assigned a unique confirmation number... and the email that the user receives after registering is very customizable as to what data is included in the email. You can make that act as your receipt and that confirmation number can be the unique identifier.
4. Change text on various screens/buttons from 'Register' to 'Buy Tickets'
All text is changeable in the language file. The buttons can be replaced to as needed.
5. Potentially allocated specific seat numbers (not essential)
This would not be done automatically, BUT you can make a custom field that is "hidden" for the event. User won't see it, but it would show in the backend so you could fill in a seat assignment there... like an "Office Only" portion of the registration form. As you can use tags to dynamically insert data from custom fields into emails generated by DT Register, you could include a tag for your hidden field and use our email function to generate an email that goes out to all registrants of the event and that could include their seat assignment.... if you wanted to send it out.
I would also like to be able to allow organizers to create their own events via the front end (and set their own payment processor details, etc.) in the future, so is there any plan to develop this in a future release?
Yes, frontend administration is coming very soon... hopefully within a couple of months.