Disclaimer: I don't work for the company or have anything to do with this project; I just found out about it via this news item. Just my 2c.
"I'm participating in lectures about linguistics" and "I participate in lectures about linguistics", without an adverb, both interchangeably mean the same thing in English
Technically maybe, but in real use, just about every native English speaker will understand the first to mean that I'm doing it right now and the second to mean that I do it habitually.
There is no viable alternative to Flash right now for streaming live video, especially with the same market penetration.
Yes there is, it's called RTSP/RTP and it's well-supported by VLC and QuickTime (and by extension their browser plug-ins). http://en.wikipedia.org/wiki/Rtsp
Any sufficiently advanced technology is indistinguishable from a rigged demo.