Wow, something new surprises me about Dolphin even after a month of using it. I didn't know admins had extra event fields.
Anyway, you look a bit new (as am I), you might be modding things soon enough if you know some php. I may be able to point you in a direction though. The events.php file is mostly a wrapper thing for the stuff in inc/classes/BxDolEvents.php. If you look at the function SDAddEvent, there are sections that limit the extra fields to admin only using an if with ($this->bAdminMode). You might want to poke around with that and run some tests taking some of those fields outside the if statement.
If you only need a few people to have the extra access, I believe moderators are implemented in this version basically as admins, so that might work too.