1.Peoples south of the Vindhya rarely submitted to the rule of the north / Delhi. The Muslim rulers had to fight dissidents often. Only the crooked machinations of the British kept south cool.
2. A break up is inevitable as had been explained by Perrier the great S Indian hero. The question is what form will this take - several states or one Deccan unit? Kerala is about to emerge as a Muslim majority. Hindi language and the high cast Brahmin are detested by the southerners. Marhathas may like to go it alone. Tamils of India and Tamils of SL may try a political combine. We are left with Andhra, Telangana, Karnataka and Gujarat.