*ahem* If I may get back on topic...
I'm a republican and a democrat (not the US kind - the philosophical kind), so I don't believe in the divine right of anyone to call themselves 'king' or 'emperor', or to hold political power without the consent of the governed. This is going to colour my views on Akbar and his secularism.
In the early days of the Mughal empire, there was no unity anywhere. Religiously, there were hundreds of Hindu sects, hundreds more Muslim ones, the Buddhists, Jains, Christians and others, not to mention syncretic groups like the Sikhs. Politically, the Muslim hierarchy was imposed on top of a mostly Hindu populous. While they claimed legitimacy from their relationship with the ulema, there was none accorded to them by the majority of their subjects, who weren't subject to the ulema. In other words, the only
legitimacy they enjoyed was force.
Akbar was a smart man. I don't think anyone can dispute that. I think he understood the complexities of imposing himself on top of a population that couldn't care less about which Muslim ruler was set over them. This was the failure of his predecessors - particularly of the two Mughals who preceded him. He also had the example of all the Delhi sultans before, and of Sher Shah who was his immediate predecessor as the prime ruler of northern India. He would have understood that for his dynasty to become established, he needed to win the consent of the people, if not directly, at least by default (ie, they don't rise up too much). He did, or at least, tried several things for this, including trying to get the leaders of all the various religions to accept his supremacy.
Abolishing the Jizya, allowing temples to be built in Brindavan, overtures to the Jains,... These were all part of the attempt. I think we should recognize him as the first Muslim ruler who came to this realisation that the he couldn't be merely a Muslim monarch.
Din-i-Ilahi is one other such attempt - an overt one, to create a religion (or religious philosophy, at any rate), which encompassed what he had learned from all the various religious leaders and philosophers he had encountered. If you look at its structure, there is One God, and the Emperor is his representative on Earth - Caesaropapism!
I think he would have hoped that he could bypass the orthodoxy - both Hindu and Muslim - whose petty squabbles he probably grew disgusted with, and establish a direct relationship with his subjects. However, nothing imposed in that way from above could really work in a land like India.
I think we should look at his secularism as equal parts conviction and politics. And in many ways, his politics
born from his convictions, and his convictions were influenced by the politics he had to play. There's no way that he would have believed that an emperor wasn't required, for example.