I've signed up for Pinboard, it has most of what you want - 3 is http://pinboard.in/u:philfreo/t:git/t:tutorial. What concerns me is the 4, due to the proverbial "network effects", delicious was so good for searching others' bookmarks because so many people were using it. I'm afraid there won't be a clearcut "winner" that everyone uses, the "go to" place to look for links.
