Let me address each of your questions. I don't think the SEC would give MS a pass if he passed along misleading or wrong info on a blog. The SEC made it clear in their rulings since Netflix's use of their CEO blog that such use of a blog can constitute be subject to SEC enforcement if not made properly
second, 5bn shares is only $1.5m at today's price. If MS is serious about developing a market in Korea for D-20 he will need most of those shares to build out the infrastructure and the distribution channel. Having worked in and around the Korean market for over 30 years it is a very expensive distribution market to operate in (much akin to the Japanese system). For a foreign company such as ECOS to penetrate it will take real moey to build out a channel.