You can definately do full control on one stick with most four channel transmitters but I think (I could be wrong) that most three channel Transmitters have two separate driving sticks (with only one channel per stick) then a knob or swich for the 3rd channel. This would sadly mean youd have to quickly move hands to operate the third channel.

And as for a wedge to beat all other wedges, that im afraid is a thing of fiction. All you can do is make the scraping edge of the wedge out of as hard a material as possible (i.e titanium), and have a really thin leading edge, almost like a plane scraping over the ground. A wedge like this though would get plauged with driving problems on most wooden floored seamed arenas...