"It is said that the vessel's nature is ego (the will to receive)"

That is not the case. Judaism teaches that every vessel has both an inclination towards Good and an inclination towards Evil. It just happens to be that in the current state of the world, the majority of vessels' Evil Inclinations predominate. Judaism never ever teaches that one should go CONTRARY to one's nature, only that one should emphasize a different part of one's nature. The inclination for evil can also, in fact, be used for good - if one understands it and how to turn it upon itself.

Regarding your further point, Rav Dessler has a lot to say on the subject of Giving and Taking. Most relevantly he speaks of 'higher' and 'lower' expressions of the two. The Higher expression of Giving is GIVING FOR THE SAKE OF GIVING, while the lower is GIVING FOR THE SAKE OF RECEIVING (compensation, gratitude, or merely a sense of satisfaction). The Higher expression of Taking is TAKING FOR THE SAKE OF GIVING, while the lower is TAKING FOR THE SAKE OF TAKING. This point needs more elaboration.

TAKING FOR THE SAKE OF GIVING is more aptly termed 'receiving' and I'll give you an example from my own experiences.

A great rabbi was visiting my Yeshiva. Afterwards he went downstairs to wait for his driver. Being in his early 90's he did not appear to be standing very stable, so one of my friends brought out a chair for him to sit on. After offering it to him, the rabbi replied "I don't need to sit, but since you brought it I will use it". My friend was left with a wonderful feeling and we were all left with a life lesson.

GIVING is the highest expression of Godliness. ALLOWING ANOTHER TO GIVE is the highest expression of Giving. When one only takes, one is selfish and just amasses stagnation. When one only gives, one is selfish and just amasses debt. When one understands that one must GIVE and RECEIVE, and do both for the sake of OTHERS and not for the sake of the SELF, then one is truly selfless and on the path of Righteousness.