Hi,
Please see response to your questions:
1. The Teams messaging mode is supported in Cisco Jabber client. Please see this video for more details:
https://www.youtube.com/watch?v=p3LrdkFbdiA
2. Cisco Jabber supports Hebrew Language. Please this URL for supported languages:
https://help.webex.com/en-us/WBX65256/What-Languages-does-Cisco-Jabber-for-Windows-Support
Also, please see below post for changing Cisco Jabber language:
https://community.cisco.com/t5/collaboration-applications/change-jabber-client-language/td-p/2178892
3. Video conference call depends on the back-end infrastructure (on-premise or Webex Cloud) that you are using.
Please rate helpful posts and if applicable mark "Accept as a Solution".
Thanks, Vaijanath S.