You can remove the Extra Fields on the Add Event dialogue by clearing any text in the "Extra field 1: Label:" field under "Events" on the "Settings" screen.
You can remove the "Venue" field on the Add Event dialogue by deleting the digit "1" from all three fields under "Views" on the "Settings" page. These are:
Event templates: General view: Upcoming view: Hover box:
Thanks, that was way easier then I thought, I was looking in the source codes!
Great.