Kimhuff,

To address part of your question, I think you need to require the convention tickets to be added to the cart one at a time.

Edit your "ticket" product and change Product Quantity Maximum from 0 to 1. This will remove the customer's option to choose a quantity. In the description, direct customers to fill out a ticket order for each person attending so they will not be confused. Each associated attribute will automatically go to the right ticket. They can add t-shirts etc separately and pay for all together at checkout.

Someone with experience in text field attributes will have to answer the rest. Hope this helps.

Glenn