It is possible to not need Java. (NOT "JavaScript", you NEED that.) I know I uninstalled Java (not script) on our computers several years ago. We don't play 'interactive online games' and I don't do skype or "online webinar joining", etc. Things like that need Java. To "get on google hangout", I think that might need Java, just like Legacy Family Tree Webinars do if you want to "join the panel" or "be there".
I just watch everything later on the uploaded webinars or youtube videos. No need for Java for that.