1. We live in a world where people learned to put aside fear and hate in favor of securing power. The witch trials and inquisition in Europe were brought to a standstill early on and instead of people with abnormal abilities being snuffed out completely, they were scooped up by the ruling classes, their bloodlines refined and their abilities glorified. Today, nearly 50% of our population is made up of the anomalous, or as the common folk call them, 'Supers'. Today the diversity and strength of powers far exceeds what we first thought possible and a new need had come forth. We need control.
I see what you're going for with this idea, but from a psychological and sociological perspective it doesn't hold together. The primary reasons people want "power" are fear (of the unknown, of losing control, of death, of becoming poor, of having family members mistreated...), and hate (generally directed at those that are perceived to be different or inferior or even less than human). It has been argued that true hate is really a mental illness, bordering on psychosis... but I digress.
So if these people have given up fear and hate why do they seek power?
My suggestion is this: Perhaps, in the cultural milieu of your alternate reality, something happened (a world-wide religious movement? Something else?) to make it unacceptable to show - or even admit to feeling - hate or fear. Wanton violence would, therefore, not only be illegal, but result in severe cultural sanction. A person even suspected of harboring such feelings would probably be sent to some sort of inquisition
-like group for "questioning" and/or "re-education". But human nature being what it is all this would do is force people to become much more subtle in their quests for power. Secret cabals would form - probably along family lines for reasons of trust. Every public action would contain layers of meaning and nuance. Conspiracy theories would become a daily reality in this world. Infiltration, manipulation, information gathering, and long-term planning would be the skills that make a cabal/sect/tribe/family/whatever successful.
Given this background the eugenics-oriented part of your plot (certain bloodlines and abilities being "encouraged" by selective breeding), would then be a natural outgrowth. Every "family" would seek to gain advantage via this mechanism once the possibilities were revealed. The "bred" people would obviously be all but owned by these families, of course. Expensive investments. Their lives would be a pampered and exalted sort of slavery. But these bred traits would soon escape into the general population - again, human nature being what it is. Some of them (maybe most of them?) would be genetically dominant traits. More and more people would be born with superhuman "abilities". In just a few dozen generations the whole semi-feudalistic society would fall apart, leaving a world with a large and expanding population of "supers".
Just my take on it, of course.