the sort of cultural difference in the case of turkey is more of a cultural nuance than a difference. it doesnt make sense to act as if a karadenizli is as different from an egeli as to be a different nationality. the difference between these come from the isolating factor of geography, not because they used to have different political histories. acting as if these used to be different countries in the past would be a fallacy. the type of rhetoric you talk about is more the case of soviet russia, which had to house romania and mongolia on the same map. this is not the case of turkey. it's even hard to distinct a syrian from a turk without language.
thinking that kurds would be safer in a federation is also a fallacy, since the threat to their security doesnt come from the central government but from local conflicts fueled by poverty and domestic agencies.
the discourse of decentralized governance in turkey is not about distributing the power but sharing the amount of governance required to regulate each region. the problem is not an overabundance of power but lack of governing coverage and funds. a federal state of turkey wouldnt be about enjoying the merits of having their own share of power, but suffer from the responsibility of having to upkeep their own. not every region of turkey has equal resources to maintain a stable economy. some regions are extremely poor and need the locomotion of the richer regions. centralized government in turkey is about distributing means and capital, as well as opportunity. unlike certain countries that were born from colonies, the main principle foundation of turkey is about equality of opportunity. this requires a fair application of rule of law. a fair application of rule of law requires a just generalization. this is impossible to apply if the country is sliced up into different departments that all have a relative definition of opportunity.
the worst case that would happen with kurds is not separation, it's if they dont separate but are left alone with terrorism and political conflicts. the region would not separate but turn into a cesspool of terrorism and extreme poverty. this would ruin the local population, not make them safer. statistics show that a dominating majority of kurds dont want to separate, but their political representatives always talk about separation. this is because the region is lacking infrastructure and education, which makes them vulnerable to having their political representation hijacked. this would only be amplified in a separate federation.
a federal state consists of many smaller states, the smaller states are constantly challenging the federal states' power.
no offense but this sounds more like a social darwinists or primitive anarchists dream to me than reality. ive yet to see any given region on anywhere on the world flourish with conflict. there isnt such a case in history. middle east is full of conflict i dont see them thriving.
also you talk as if there is absolutely no centralized governance in turkey. we already have centralized governance. it's just not a federation like in soviet russia or usa, which were both rich and powerful for reasons completely different from being federal countries.
human rights are not relative to the condition of the individual, everyone is equally subject to them. the means to deliver these rights could differ depending on the conditions of the individual, but the main principle is a generalized rule of law that can be applied to everyone equally. isolating individuals to their own devices and leaving the alone with their problems would be devastating for turkey. the political division would be the least of such concerns.