[Anypeny]

In my opinion, the question is not whether Buddhism needs supernatural/super-normal/supra-mundane stuff, but whether a practitioner needs these stuff.

Just like the description of jhana states might seem supernatural/super-normal/supra-mundane to non-practitioners, for most of us on this website, we merely accept these descriptions as 'states' that we might encounter during the progress of our practices.

Most of these supernatural/super-normal/supra-mundane stuff in Buddhist Texts are merely answers to questions that a practitioner might encounter in his/her practice. As a practitioner makes progress, he/she will slowly understand what these stuff means.

So there is no reason for practitioners to be making true or false judgement calls regarding these seemingly 'unbelievable descriptions.' Just because you haven't experienced it, it doesn't mean it is not true, and just because you read it, it doesn't mean you know what it meant.

But, there is nothing wrong with practicing Buddhism in a secular fashion, it is all a matter of choice.