Hi,
Thanks for the interest in our plugins. I can answer your questions.
There is a template that can be modified for the email tickets, but out of the box it does not include a way to add a custom message per event. It is possible that could be done by adding a custom field to the event and then showing that field in the ticket.
The template is called email.php and you can find out how to modify it using our themer’s guide:
https://theeventscalendar.com/knowledgebase/themers-guide/
Beyond that we are limited in supporting customizations.
Currently, Event Tickets Plus and all our ticketing plugins are not compatible with WPML and I do not have a timeline when they might be.
Let me know if you have any follow up questions.
Thanks