I don't think you can include apologetics or even theology as part of having a fierce, honest, secular debate on Jesus or religions. Apologetics and theological discussion already implicitly involve the assumption of truth, which prevents a truly strenuous, secular debate. As soon as you bring the claims of religions, with all their impossible-to-prove truth assumptions, into the debate, you're no longer having a secular debate. You have to leave the assumptions of divinity, faith, gods, afterlives, etc. None of these things can be adequately defined outside their self-referential religious contexts, and thus the very concepts that ought to be discussed in secular debate can hardly be given adequate definition to inform and frame the debate.

Comparing the persistence of Christianity to Baal and Thor is, I think, just this side of intellectually dishonest. If you're going to discuss comparative religions and their place in the dustbin of history, then like with other such comparative discussions, you shouldn't be making comparisons to things long since dead, especially myths. Instead, you're up against other extant religions with their own rich and ancient histories—Judaism, Islam, Buddhism, Hinduism, etc.

More importantly, the persistence of any of these religions provides no informative or measurable proofs of their truth claims. At best, we'd be delineating the ways in which they provide subjective meaning—but that tells us nothing at all about their objective truths. We cannot really say we've identified any of Jesus' flaws, given that the sole information available are stories written long after his alleged existence, all of which claim a god-man free of flaws. We can critique the flaws of his followers, but that still doesn't inform any objective and secular discussion of the truths and meanings of religion.

It's true that billions find meaning in their chosen religions. Millennia of effort has provided no conclusive evidence this is anything other than subjective, though.