Subaru Genuine E361SXA201 Yakima Kayak Carrier, 1 Pack

Yes. It works with the aero bars as well as square or round bars. You'll need to buy the rubber mounting brackets separately. They come in packs of four.

I can't confirm for the 2016, but I have a 2014 with factory installed "aerobars" (they are wider than they are tall) and I had to buy the clamps with the Subaru part number: E361SAJ801

The kayak rack itself is just a Yakima rebox, it will fit anything on any roof assuming you get the right clamps.

Yes, mine is 12' and does just fine. I'd recommend at that length you also use the kayak tie downs at the rear and front of the vehicle.