I don't know how many MMOs you have played, but griefing takes
many forms. It's not just simply impeding some other clans raid.
And yes, I stand by my statement that anyone who feels griefing is okay, does have morality issues.
So you'd put them in the same boat as child abusers, child molesters, women beaters, and vegans? Those are the kinds of people I consider having morality issues.
From certain philosophical standpoints, an immoral activity is an immoral activity. morality itself is a ideal in of itself, and is not subject to a quantification from this point of view. Something that is a moral good is good in of itself. something that is bad, is bad in of itself. Of course as a society, using the typical moral lens that society uses, we diversify and categorize evils, and place degrees on things, in a manner where it could be quantified. So to answer your question it would come down to how you view morality, is it an abstract ideal that we can strive to achieve, that cannot be quantified or justified? Or is morality a more complicated issue in which some actions are less evil than others, in which actions can fit on a scale and be quantified.
Looking at the act of griefing there are three parts, the motive or intention, the action (or the means), and the results (or the ends). In all of the above examples the intent or motive was to cause another harm, so if you view morality as analyzing intentions, then yes, all would be immoral, and all would be in the same boat, although you could go further and ask if all bad things are equally bad, and if you answer no to this, then you can separate them out by degree of badness. The means all vary, and if you believe morality stems from the actions itself, not the intention or the outcome, then it would vary on what the exact mean or action was as to whether or not the action was immoral, and from there comes the debate over whether or not morality can be quantified. Lastly would be that which looks at the outcome, but ignores the means and intentions, all the outcomes are a wide variety, for example you could try to grief a raid and fail miserably, according to the person that looks at outcomes, you did nothing wrong. And once again from here the second debate follows as to whether or not morality can be quantified, although typically a consequentialist or utilitarian approach to ethics would argue that morality is quantifiable.
So to answer your question, it depends, but On all three aspects of analysis I believe it is safe to say that all the above actions are immoral, so they would all fit in as being immoral actions, but as to whether or not morality is an absolute value, or a value that can be quantified, would determine if one action is worse than the other.