sorry for the delay in responding.
Sure I used to sail the Outback & enjoyed it well enough but altogether the Adventure is a better sailing experience (better than all of the Hobie boats including the AI IMNSHO).
The reasons are a) that the Adventure is a faster boat so it goes better under sail, pedal & paddle and b) the Adventure has a daggerboard which significantly improves the boat's upwind performance (important in the tidal waters that I sail in).
The reason I prefer sailing my Adventure over sailing the same hull as an Adventure Island is that it is more of a challenge to sail the Adventure well than it is to sail the AI: there's no danger of a capsize in the AI. Also the AI is a whole lot heavier and complicated to transport and set up and, should the wind drop, it will not be as easy to pedal back. Sure the AI is faster - but the overall sailing experience is a whole lot wetter (as long as you successfully avoid a capsize) ! Finally, I usually pedal/sail out, fish and then pedail/sail back -I find that fishing from the Adventure Island is more difficult thant the Adventure because of the problem of fishing over the amas and stowing the mast out of the way.
Anyway, your question was about the Outback - go for it ! It sails well enough as long as you recognise that it is not going to sail very well upwind and you plan your sailing trips accordingly.
The sail kit works perfectly OK "out of the box" -- a couple of mods I would make would be to:
a) buy 2 small turning blocks through which to lead the sheet (i.e. the rope tied to the sail to alter the sail's angle to the wind) so as to reduce friction in the rope - that way if you need to de-power the sail in a hurry (to avoid a capsize) you can because the rope will run so much easier through the blocks. On my boats I have tied (i.e. no holes in boat!!) with light line, one block to the rear padeye and one to the plastic padeye in the RHS of the cockpit to the front of the parcel tray. From the helmsman's right hand the sheet then leads forward through the block in the cockpit, back through the block at the rear padeye, up to the sail. Because the sheet now comes to the helmsman's hand from the front of the cockpit, a pull (rather than a push) pulls the sheet in (which I find more comfortable and logical)
b) tie a small loop of bungee somewhere in the front deck area (I have an Adventure and I tie this loop to the bungee that holds the front hatch lid shut - but I do not think the Outback has the same lid so you will have to experiment to finsd a place to tie it - I am sure there'll be something in about the right position). This allows you to take down the mast roll up the sail and secure both to the front of the boat by poking the mast foot into the loop; the mast will lie fore & aft along the gunwale of the boat beside the helpsman's seat. If you have a rod in the rear rod holder this will stop the mast sliding off into the water but you may need to add some kind of bungee-strap-with-hook on the gunwale behind the seat to properly secure it. Now you can take the mast down & stow it & put it up again whenever you want simply by hotching forward in your seat far enough to put the mast into the mast base & secure the sail foot - the procedure to deploy is: 1. Pedal & steer so as to point the boat directly into the wind; 2. Remove rolled up mast & sail from bungees & place it in your lap across the boat (tie the sheet to the "clew" if not already tied on - I always leave mine tied on and release the sheet from the cleat if cleated); 3. Hotch forward in your seat to access the mast base, unhook the sail "gasket" line (if you have one, which you should) from the hook at the clew of the sail so that the sail will unroll & push the mast into position in the mast base; 4. Pull the sail out so that it "unfurls" (i.e. unrolls) from the mast - if you are still "head-to-wind" it will flap harmlessly; 5. Secure the bungee at the foot of the sail to the hook beneath the mast base; 6. Hotch back into your seat; 7. Pedal/steer onto the desired "tack"; 8. "Sheet" (i.e. pull) in the sail and sail away under the admiring gaze of the surf bunnies on the shore who have been watching your progress with great interest.
c) you might want to install a "clam cleat" to belay the sheet while sailing so that you can sail hands free - you only need a very small one and there are various models to choose from - I used one which fitted onto a wedge to angle the cleat towards the rope and which had a thing called a keeper around it to stop the rope from catching on the cleat unexpectedly. Worked really well - always gave a positive release of the sheet and was very adjustable. I placed mine on the vertical wall inside the parcel tray of my Adventure did require drilling though!).
When you want to push the envelope/get more speed in light winds it is possible to add a foresail (jib) but this really requires that you stay (i.e. support) the mast with "wires" (I use very light spectra line). This is a great addition but adds a lot of complexity and even in light winds it requires a methodical approach and a clear head to avoid a ducking... turns a sailing toy into a proper yacht though ! I have posted elsewhere on these forums about this mod if you are interested.
Hope this helps. Enjoy