If you are using the OOB Events web part, the page to create new event from the "Add event” button is _layouts/15/Event.aspx and does not support customization.
These are built-in controls on this modern page and cannot be modified or removed.
Removing the columns from the Event content type will not have influence on this page or the Event list.
Assuming the Status column is a choice column with choices “Pending”, ”Approved”, ”(leave empty)”, here is a sample formula for validation:
Based on my understanding of the requirements, I'm posting the below.
Here is what it validates:
if [Status]=Pending, will not allow to select [OutCome] or enter [OutComeDate]
if all 5 content type outcome columns are entered (not blank), force to select [OutComes] and [OutComeDate]