Apologies in advance if I'm posting double here -- I suspect I'm far from being the only one with this problem. I've been looking for months now, so either I'm using the wrong keywords or the solution isn't as simple as it sounds.

Similarly to lilbebel's question here, I'm building a shop which sells tickets for events. I'm not great with php, so I'm trying to use standard Drupal & Drupal Commerce functionality as much as possible.

The process basically would be:

1. A user hits the register button for a specific event
2. The user doesn't need to register an account -- tutorial here
3. An order is made, but the cart process is skipped -- tutorial here
4. The user fills in their name & e-mail address and selects options for payment
5. The user is redirected to an external payment site (iDeal, for example via Mollie)
6. Upon returning, a Rule should check if the payment succeeded
7. If so, a ticket number or code should be generated
8. An e-mail should be sent to both us and them.

I'm pleased to say I've gotten up to the point that something can be bought in the shop anonymously, without the cart, and then paid for. Also, the Commerce Tickets module seems sufficient to gather the buyer's info.

However, three things remain:

1. A ticket number or code should be generated. Preferably something I can customize, like [code for event] [date of event] [order number with leading zeros].
   But where should I start? Some sort of hidden custom php field on the order itself?
2. Can a rule check if the payment was done? I know there's the condition On Checkout, but does that mean the same?
3. If all's well, an e-mail should be sent -- containing their name, the ticket number and formatted prices in a html-layout. How do I go about gathering this information and putting it into an e-mail?

If I can just wrap my head around these last parts, I'd be good to go. Hopefully someone can help or give me a push in the right direction for any of these.

By the way, I'm also willing to make a complete tutorial of the process once it's done. Considering how often people ask me if I can build their ticket shop, I would say lots of people are served with the knowledge.