When scheduling the event there is an option Entry & exit tone: which you can change to No Tone.

You can edit the meeting type up until the time the meeting starts.

You can just shared a specific screen:https://help.webex.com/en-us/5ddww5/Share-Content-in-Cisco-Webex-Meetings-and-Cisco-Webex-Events 

I have not found a way for admins to do this.  The executives/VIPs need to allow it:https://help.webex.com/en-us/nub7z8c/Allow-Another-Host-to-Schedule-Meetings-or-Training-Sessions-on-Your-Behalf

I have had issues as well with Webex, VPN and Windows 10.According to best practices:Turn off VPN. Your employer may have provided you with a VPN (virtual private network) service that allows you to use the company network while working remotely. Oft...