I have no experience with the Frenzy but have been using a Titan 15.5 on snow all winter thus far. The Vodoo and the Titan have the same bar/safety features so I can answer your questions as far as the Vodoo is concerned.
Using the Flysurfer on snow by yourself is no problem at all. Launching can be done either throught the middle or up the edge of the window. Before the kite is fully inflated a launch through the middle of the window produces very little pull and is quite safe. If the kite is leading edge down on the snow fully inflated it is easy to walk the kite across the window and launch by simply pulling on one of the brake lines. Launching by yourself never takes more than a couple of seconds, throught the middle or up the edge of the window. The http://www.flysurfer.de
website has a short video on the launching of the Titan using various methods.
Landing is equally as simple, just let go of the bar and the kite flys backwards down the window and lands lightly on its trailing edge. When hanging off its leash in this position the kite can still generate some pull in high winds. If there is enough snow you can attach the leash to your snowboard binding and dig your board into the snow to secure your kite, some people carry ice awls to screw into the ice and attach the leash there. If it is really blowing and you need to completly colapse the kite just pull one of the brake lines in a couple feet and the kite lays out completly flat with no pull at all. You can wrap the brake line around your binding a couple times and the kite will sit there all day and not even flap. Its a great system.
I haven't had the chance to fly the Vodoo yet but one of the local riders here, Mike from http://www.kiteboarding.ca
is the Canadian distributor for Flysurfer and has been ripping on the Vodoo 10 meter the last few weeks before Xmas. He is pretty stoked about he kite, it looks pretty cool. The range of this kite looks enourmous. He has been flying the Vodoo 10 while I have been out on my 15.5 in really light wind. Looks like all the bridle adjustments really extend the wind range. From what I saw the kite flys and turn really quickly. I think the new Spirit should be available soon, this kite is same as Vodoo but a little heavier fabric and aluminium vrs. a carbon bar, supposed to be a bit cheaper.
I'm really pleased with my Titan, it was a great purchase. I'd recommend Flysurfer product to anyone.