Yea, that bug happened because you interacted with the door from quite far away. But it's good that I know this bug. Will fix it in the next update.
Save points is for the fullgame. Because this is only a ~20min demo.
And that enemy behaviour is to balance it a little. But this will change in the full version with new animations.
For some people, the game is too difficult and for other people it's too easy. So I had to find some kind of (temporary) balance.