Wrapped spins are a whole differnet animal than handle pass.
To address you Q's. When I do wrapped spins of any sort, there is zero tension on my back hand. Any tension on this hand will twist your hips, you will run the spin and get yanked off axis. 100% of the line tension needs to be on your front hand. I usually take a more squated out stance when I approach the wake wrapped this seems to help cut down on the line tension. The only real similarity beside the rotation aspec is that when you leave the wake you still have to inititate your rotation. If you just left go off the wrap handle again you will get yanked. Once your in the air pull the lead handlejust likey you would for a Handle Pass spin, this will keep you on axis. As for you handle placement Q- the position of your front hand is more important than your back hand, you really wanna try and keep your elbow at a 90 degree with your arm and elbow tucked into your hip tight. This will keep you from twisting your hips on the way into the wake. IHope thie helps man, post up some video when you go try them, dont forget to get a nasty poked out grab in there!