Not necessarily - if it works offline (without internet), that also satisfies the "privacy" requirement for many of us.
Not necessarily - software can collect data offline and then send a payload at a later time.
It definitely can! However that is easily verifiable. First is that. You can see in the network tab that nothing is uploaded Second is that you can just close the tab before enabling internet. It’s not possible to send payload if the webpage is gone.
Either way I’m not collecting video information. It’s gonna bankrupt me just on storage fees given how videos are so large