I think this is mostly due to the highly polarized political climate. California is the most populous state and it's policies frequently end up spreading to other states and therefore is frequently focused on because if it's major influence. This is similar to how Texas and Florida are in the news a lot for their more conservative policies. While there are people out there who take the time to inform themselves and make their own decisions most people are only able to parrot back talking points they hear from the news or their friends. I suspect your coworker is one of those people and probably leans conservative so all he hears all day is how California's policies are making housing too expensive and it's too "woke" etc.
Ward
It has federation so you can talk with people or rooms on other servers. There is also voice and video chat supported by matrix but I'm not sure if conduit has that yet. Also smaller things like picture and emoji support. Irc is a much simpler protocol so you give up a lot of functionally over matrix. In the end just pick whichever one has the people you want to speak to or set up a matrix bridge to irc and speak to people on both if you don't mind self hosting
Either you need to expose those two services to the Internet or use a VPN. You mention vpns are inconvenient but have you checked out tailscale? The free account does your needs and it's by far the easiest one I have set up. You can also look into a cloudflare tunnel but you would need a domain name for that
This is an accessibility feature. My deaf friend uses it because he can't hear the chimes and wants to know about notifications even if his phone is on the desk. That being said, it would be super distracting in a meeting.