Keith,
>Does jitsi create rooms upon demand from anyone?
Jitsi has two main methods of operation that I know of:
o create an "on demand" room by generating a unique string that you can pass to the other people and everyone joins via that string
o create a "moderated" room which has two URLs generated, one for the "users" and one for the "moderator". You get this type of room by clicking on "book a meeting URL" right under the normal window that says "start meeting" at the top of the Jitsi Meet page.
With regards to the sound, I have a Thinkpad X1 and when I use the 3.5mm audio jack on the side I have not been able to get the microphone to work properly, so I use a USB sound card or USB headphones to hear and speak. This requires me to configure the sound options on the system. You can also select which speakers and microphones you want to use in the Jitsi application itself right before you "join the meeting". Just click on "settings". You may have to dicker with the volume a bit in your system settings.
On the other hand my X1 now uses solid state storage and has a very soft fan (if it turns on at all) so sometimes I do not use any microphone or speakers other than those with the laptop.
md