ORIGINAL: -pkh-
Elevon mixing takes your aileron and elevator inputs and mixes them together to control two surfaces. V-tail mixing takes your elevator and rudder inputs and mixes them together to control two surfaces. This allows a single pair of control surafaces to act as an aileron & elevator or elevator & rudder simulataneously.
Exactly.
On a Hitec or Futaba radio, Elevons mix Channels 1 and 2. V tail mixes channel 1 and 4.
Elevons are primarily used on flying wings, such as the Zagi planes, or delta wings, such as the micro jet and twin jets.
V tails are very popular on sailplanes and some parkflyers.