Hey @Stefano,
Thanks for reaching out!
What you describe should indeed be possible with JUST Community Events—you do not need Community Events Tickets for these features.
Essentially, what you can do is set the default status for submitted events to “Draft” when they are submitted. This is the default setting, but you can confirm this on your site by going to Events → Settings → Community in your wp-admin and ensuring the Default status for submitted events option is set to “Draft” (or “Pending Review”).
So then events will be submitted, and will not be published immediately. They’ll be “Drafts” in your wp-admin, which you can filter easily by using the filters like the one shown in this screenshot:

You can then edit these draft events in your wp-admin to manually add tickets as you describe, to your specific standards. Then you can save the tickets and “publish” the event, and the tickets will work just like normal.
I hope this helps!
George