You have found the correct options. These are all good choices, and you seem to understand the trade-offs.
The camcorders you mention all work fine in auto mode - turn on and just shoot and you have a good video, so there is no real learning curve unless you are shooting in difficult circumstances or going for creative shots.
The zoom on the GW77 might be useful if the riders are not close - the Samsung lens is really a wide-angle. The LCD screen is on a double hinge, so it is not easy to break - it just moves; plus it is sturdy and the cameras a whole is shock proof.
One other point - the Samsung does not have good stabilization, so you have to concentrate on holding it steady (it can be done). The optical stabilization with active mode on the GW77 is very good, and so you do not have to be that steady, plus you can actually walk while shooting. Less to worry about.