[Forrest]

#1 already exists in OW. click and option+drag a tab.

#9 exists on the OS level, but not quite as pretty.

The author isn't very good. He titled the article "10 Features You'll Find Only In Opera" - well, as I pointed out #1 already exists.

#4 - isn't that what the green button does in OW?
#5 - I'm not entirely sure, but it sounds like the little down arrow next to the back button, or the orange arrow in safari's address bar.
#6 - Sounds like a watered down version of workspaces
#8 - Same as OW, depending on how the page was generated
#10 - OW does the same thing.
#12 - Same as OW