Welcome to Opera forums @Napwow!
Point # 1:
Many of us are wainting for that too, I think the request is already made.
Point # 2:
It's already implemented, just it's that the SD it's intended different for every computer, so once you synced, look in bookmarks tree, look for "Other SD" and then just have to move/copy the SD entries to the current SD computer.
Point # 3
Hidding tabs it's Tab stack? Group them? Well... I suppose it's requested too.
Just pinned tabs it's actually implemented.
Read Before posting a Suggestion/Request...
Because your avatar does not seem to have had a good nap. xD