This isn't a new concept at all. The points you raise were those first thought through by Atkinson and his work on how to measure poverty in the 1970's that led to Sen's development of the human poverty index that the World Bank now uses.  But it turns out that even when you look at just the standard economic dimensions of well being, correcting for equality in one dimension causes pretty wide disparities in others - such as how women or other minorities are experience life, for example. How one defines poverty is actually a pretty big exercise of power in itself.  

That's why Sen developed the capacity approach.  Focusing on equality of capacities to achieve and capacities to be is really the only way to achieve a semblance of equality in even the standard economic measures of well being.