From version 3.3 on wards, amr-events now has three optional additional roles:

• Event Contributor
• Event Editor
• Event Manager

If you wish to keep your event creation separate from your post creation, these may be useful.  If you are updating the plugin, you may find that you need to force an update of the various roles (even existing admin may need capabilties manually added).  So while one hopes not, just in case:  use a role manager like https://wordpress.org/plugins/members/