The lithium has worked out great so far. I've easily been able to get as much life out of the smaller, and much lighter, 30 amp hour battery asI did on the 80. I'm not certain how safe the lithium batteries are with exposure to moisture. I've seen some scary videos of what they can do when exposed to the air and I have no idea how they react to water. I keep it tied down to the front netting (which it easily handles) and figure at worst, it burns through the netting and will drop through to the bottom of the lake eliminating any danger to me (not so much for the fishes).
To be honest, I don't use reverse that often to answer that question. You can rotate the thrust in any direction up there, so if the wind isn't fighting you too much you can pivot around pretty tight. If your fighting the wind, forget it. That little motor just cant match the force sideways on the hulls and sail.
All in all though, the thing has worked out great getting me out of the middle of the lake when the wind just completely dies. The only complaint I have is when I go solo, it's hard to deal with the steering at he stern and motor control at the bow. If I'm on my own I tend to lock the tiller and use the thrust to point me in the direction of the dock and that actually works out OK. With two people though, it's great. When not in use, I just fold it over and lock it up out of the water and you hardly know its up there.