Of these I think option 3 makes most sense.
I agree that it’s a bit too hidden. Perhaps the + icon could be available to be added to the post menu, that works the same way? And when a topic is closed, the reply button is changed to + New Topic as I think has been proposed elsewhere.
Unfortunately I’m distracted with getting ready for a trip (meetups in Berlin, Toulouse, Dar es Salaam this summer, anyone?) so not really able to focus properly on this, and feel a bit uneasy about the big changes coming without being able to properly pay attention to them. But I’m liking the direction this is taking! 