There's no way I know of to do this without altering core EVENTS code.

You can get part of the way there with a small JavaScript hack (see below) that will remove the "DELETE" option from the event DETAIL view for all user roles except HOST or ADMIN.  Unfortunately you can't use the same trick to remove the "DELETE" option from the event EDIT page.

Script Hack
In case you're interested, here's one way to hide the "DELETE" option from the event DETAIL view (without altering DNN code) for all users except ADMIN and HOST users:

In your EVENT module's SETTINGS->ADVANCED SETTINGS->FOOTER, add the following code:

< script >
  if (!document.getElementById('IconBar.ascx_cmdInstallModules'))
  {
    try { document.getElementById('dnn_ctr(your EVENTS module ID here)_Events_EventDetails_deleteButton').style.display="none"; }
    catch (err) {}
  }
< /script >

That's it. You can find your EVENTS module ID value in the page URL (your browser's address bar) while you're on the module's SETTINGS page.  The module ID is the value that follows "ModuleId" in the URL.

-mamlin

I believe if you edit an event that is moderated, it will need to be re-approved. However, I don't think a deletion needs approval. Perhaps you would like to raise this as a request on Gemini. The details are in my signature.

Cheers
Roger