Dear Friend,
Some direct answer of your direct question.
1. You can use vmotion for plan activity, whether HA work on accident activity.
2. Vmotion work without cluster, but HA work in cluster only
3. Whether HA sub components DRS use vmotion technology for function.
4.HA work on active:Dead host, whether vmotion work on Active:Active environment.
Thanks & Regards
NK