I do think that motive towards profit is indeed part of human nature. Denying so dehumanizes capitalists and hence alienates them, which isnt very productive in the study of capitalism given that they are just humans. Shitty humans most of the time, but humans nonetheless.
That is also to say that even with an element of profit motive as part of human nature, its existence as such (in the form of a desire) doesnt justify its constant exercise and normalization on a grand societal, collective scale.
To your second question, Yes, I do believe that capitalistic pursuits are purely from selfish and self-preservative motive, with a skrewed perception of the idea of "survival of the fittest", it is a desire to build a small empire of your own self. The only reason a capitalist may grow their scope of the share of capital is because they need people to collaborate with them in their pursuit of acquiring capital, and people wont collaborate without their own self interest being met. In that sense, a capitalist, however empathatic they may be, "tolerates" their workers to atleast some degree and will never be able to see them as their equals. The workers are just that, workers. A part of the capitalist's machine that is expendable at will.