Good evening Markus and welcome to the Events Calendar Support forum!
Thank you for reaching out to us and for your fantastic words.
We are glad you like the plugins.
I would love to help you with this topic.
Any plugin that supports custom post types should work.
As far as I know the most popular one seems to be https://wordpress.org/plugins/wp-postratings
I would recommend using the ratings on the events of a specific category rather than on the tickets.
Let me know if that helps.
Have a great day!
Geoff B.