Hi – great questions!
1. allow us to charge a service fee?
You could certainly factor a fee into the ticket price. Beyond that, tickets are simply regular WooCommerce products, so you can potentially treat tickets like any other products and apply WooCommerce functionality to them, too.
2. track affiliate sales? For instance, if multiple people are promoting the same event to keep track of the amount of sales for each person?
Tracking affiliate sales isn’t something WooCommerce Tickets itself is built to do and I don’t think WooCommerce itself will, either (though do check with WooThemes about that!). There are probably some dedicated affiliate plugins you can leverage here though and there may even be dedicated WooCommerce addons to assist with this.
3. check in application for tickets at events?
We do indeed have ticket check-in functionality: check out our new user primer for an overview (including videos) to get a better flavour for what’s possible.
Thanks!