1a) i dont know, but I'm sure some of these other points aren't right
1b) true, in the official product offering, but scaffolding was there
2a) false and true (thanks to burn rate and earlier assertion being false)
2b) true (price required plan not supported after purchase) and true
3a) false (multibitrate Windows Media was fantastic with a great video and audio codec, while Flash was plain bad till H.264), and in the years you say there wasn't demand, we built a similar business that routinely helped customers reach hundreds of thousands or even millions of viewers at a profit for them and a profit for us.
4a) YouTube (non-essential/comedy/ugc content being perfect for a ubiquitous animation player supporting a crappy codec via pseudostreaming) isn't Hulu, and isn't Broadcast.com. Hulu secured content users want to pay for.
Yahoo needs users' attention.