I don't think it's possible. We're created with the drive (can't think of a better word, sorry...instinct? Gah...) to value our selves, and even when we're being "unselfish," it's still because there is a gain, whether it be emotional, financial, or something else. But I suppose if you really love Communism and are hard-wired to it, then maybe...but I doubt it.
Its impossible to know every single motive for someone's actions. Even the most giving, unselfish acts can be driven by a desire to do good for others, therefore satisfying a need within one's self, thus being construed as 'selfish'.
Just.... I absolutely love doing things for other people, making other people happy. Volunteering, giving genuine compliments, cheering people up -- I love it. But, in a way, this is selfish. I benefit from it in that it makes me happy. So.... if you look at it in that light, it's impossible.
Yes? Both, depending on the situation. Usually just because... making other people happy, generally, makes me happy. So.... I don't even know. It could be selfish, depending on how you look at it.
It is subjective, but I'm asking for you to provide a situation if you think it can be done, or to simply rebut anyone who does provide one if you think the opposite.