Hey, so for the first problem (movement cost) make sure to set PathfindingCost in the ability you are using (BP_Ability_MoveAttack) to FromPathfindingCost. If not all movement distances cost 1 AP. Also, when you use BP_Ability_MoveAttack the last action point is always reserved for attacking, which is why you are seeing one less movement than expected. You can switch to BP_Ability_Move or modify BP_Ability_MoveAttack.
For your second problem (with Game Over), I’m not sure what is going on here, since I can’t see the entire game over function in your video. My suggestion was to have a new variable in the game over action where you can set the name of the level to load.
For your third issue you should not change the AttemptDestroyAction function in BP_Action. If you do so it will cause serious issues. What you need to do is to delete the overridden interface event in BP_Action_ModifyHealth (you can find it in the function list under interfaces. Select the function in the list and delete it).
This is enough for your puppets to not be destroyed. However, they will still turn invisible when the death animation is done. Then you need to disable this bit of code:
