Hi,
Sorry for the delay in responding.
I can help answer your questions and provide some insight into fixing your issues.
1) Is it possible for an event to have no end time?
Unfortunately there is now way to have an open ended event they all need end dates.
2) Google calendar export option is missing from calendar page
The Export button that is there is for Google Calendar, Apple iCal, and other compatible apps. On the month view there is just the one export button. Individual Events have the two separate buttons.
3) Some of the fields such as Organizer and Venue are missing :
Organizer and Venue are Titles for the section and not references so they do not by default have a colon.
Not sure why your “Cost” Has an extra space, it appears to be coming from a customization.
This is the default view we have for the events which shows how the plugin shows all the information including which have colons.

Let me know if you would like anything else.
Thanks