H Dakini,
Yes I believe in karma - otherwise i wouldn't be a Buddhist. And since i believe in karma, I believe that there is no point getting upset with anyone. My Guru teaches me that whatever we suffer, we have created the causes for it. Therefore, we have to accept, let go of our disappointments and anger because these deluded emotions do not serve us.
If something is not right, of course we should try every avenue to change it, but with the correct motivation - to benefit others - and not out of anger or any negative emotion.
My Guru told me about an elderly monk who had been physically tortured by the Chinese during the invasion. This monk - while under torture - kept sending loving kindness to his captors - and has never felt any negativity for them. He just accepted it as his karma and prayed that whatever he suffered, may he suffer it for others and may all the sufferings of others come to him. What a holy monk.
Because of our Protector practice, we may have suffered in the past, may be suffering in the present or may suffer in the future. How we react under duress will show how we practise the holy Dharma.
On another note - i don't get why people can get so upset at DS. If people think he is a spirit, then they don't have to propitiate him. And like you say, DS practitioners will collect their karma for following a spirit, right?
So many different schools practise different deities and people don't get upset. If they talk about sectarianism - i don't see it at all. Also if certain DS practitioners act negatively, i don't think they represent ALL DS practitioners. In every faith, in every school, in every culture, you will get the occasional oddball. They will kill or steal. It's a fact. But they do NOT represent the entire religion or culture, right? Hypothetically speaking, a manic Christian/Buddhist/Hindu kills someone, you don't say that ALL christians/buddhists/hindus are murderers right. So people label shugdenpas as murderers because some ALLEGEDLY killed someone. It's not even proven that they did!
Sometimes the world is totally mad. Stop the world, someone, i wanna get off!