Happiness, true happiness, is an inner quality. It is a state of mind. If your mind is at peace, you are happy. If your mind is at peace, but you have nothing else, you can be happy. If you have everything the world can give - pleasure, possessions, power - but lack peace of mind, you can never be happy.
That the caste system must be abolished if the Hindu society is to be reconstructed on the basis of equality, goes without saying. Untouchability has its roots in the caste system. They cannot expect the Brahmins to rise in revolt against the caste system. Also we cannot rely upon the non-Brahmins and ask them to fight our battle.