Ok, question 1: Do I have to take one of these actions? Or can I just activate, do nothing and end the activation.
You must do something...no pity for sleepy miniatures
. But a mini cannot shoot if it is engaged.
Question 2: What if my model has been immobilized? I cannot perform any of the above actions now. Do I automatically end the activation? Do I initiate a melee combat against the enemy and roll no dice?
Each time an immobilized miniatures is activated, if it is in an opponent melee zone, one ennemy minature ( to your adversary choice) attacks it, and you cannot reply. Consider it as a punching ball fr the duration of its Immobilization state.