Pretty sure i fixed all the issues you mentioned. :)
The being trapped wasn't an issue while developing the game (but it was a common issue with my current Godot release apparently):
godot error cannot call method 'change_scene_to_file' on null value
Error & work around i found:
https://github.com/godotengine/godot/issues/85852
get_tree().change_scene_to_file("res://some_scene.tscn")
get_tree().change_scene_to_file.bind("res://some_scene.tscn").call_deferred()