"Protests must be polite and not ruffle any feathers" is what I'm hearing.

I don't think that protests have to be polite, however protests do have to be productive. If your environmental group's political agitation only results in turning public opinion away from the greater movement......I'm not sure if that's a productive use of political capital.

I think it's perfectly reasonable to question a group's motivation who are participating in unproductive political agitation. Especially considering that their funding comes from an oil heiress, who could be using her vast fortune to be lobbying to the people whom actually have access to the power that can bring about real change.

the protests will only become more radical.

I'd hardly say paying some teens to "vandalize" a painting that your family owns is really a radical act of protest. Now if they were conducting these types of actions against oil companies, or the political bodies who support them..... That would be radical.