very valid observations and thank you for taking the time to look over my project!
I have actually decided against the vertical "progression", in favor of horizontal "progression". Instead of trying to be clever, I really want the process to be seamless and require no learning at all. The swipe functions only suppliment the process, there should still be a traditional way to go back and forth in the ticket-ordering process (buttons).
I did actually have this part sketched out on paper, I don't know how I forgot to include it. You're right, though! An indicator of progress will give the users immidiate feedback, visualize their goal and reduce uncertainty.