Hi Jon,
Thanks for checking out our plugins!
You can do this with Event Tickets Plus! There is no limit to the number of fields you can add, but keep in mind that these will be for each attendee in the ticket order, not for the overall order. So if you have 25 questions per attendee, you could wind up with quite a lot of questions on the screen for an order with several tickets.
We don’t currently have a demo of these fields, but we do have a demo of how the ticket order area on an event looks over on wpshindig.com. I took some screenshots of the admin area and the front end form for you. We also offer a full refund within 30 days of purchase, so feel free to test it out!
Please let me know if you have any more questions!
Thanks,
Jennifer