1. You can generate a CSV export in the backend at any time, but it is never automatically emailed to anyone.
2. Frontend event management was added in version 2.7. Also JEvents is no longer required.
3. Yes, there is a CSS file that controls the colors used in the event display. Also you can replace any of the buttons with your own custom versions if you want to.
4. The admin notification email for the event is not a dropdown as the input field enables you to enter multiple email recipients. If you are referring to something different, let us know.
Regarding #4, I only want 1 person to receive the registration email. However this event may have 3 different coordinators throughout the year. How would that be handled? Would I just have to update the email address in the backend every time?
5. Is there any validation on the input fields, like only numbers, only text, email address and mandatory?
If you want to change who receives the notification email, you would edit that setting in the event.
For validation, you can set fields as required... email fields will require an email format to be entered. There is not presently validation options like numbers only.