Theory of Eternal Recurrence

The acceptance of causality (it is not clear that humans can avoid accepting causality) makes it so.

I advise more research into this. You will quickly find that it (the big bang included) is a secular theology / creation story, scarcely more valid than the cosmologies that came before it.

I've not read any of Nietzsche (although I had wondered if you had, because of your avatar) but I would suggest there are easier ways of arriving at a laissez-faire approach to personal life than by his philosophy. To begin with, the eradication of unchosen positive obligation and original sin from your psyche can begin with therapy, and the adoption of a rational skepticism prevents one being bogged down in the prejudice of others. The selection of a code of ethics appropriate to your nature will help with much of the rest.

For all of the philosophy I have thus far studied I remain relatively unconvinced that much of it is necessary to live a eudaimoniaic life. Mostly what ails us, for the most part, is poor psychological health -- which, like any other branch of medicine, should be treatable without need of the patient first learning medicine.

Also don't forget that Nietzsche went insane. His philosophies didn't work out so well for him. That doesn't say anything about their rational validity of course, it's just something worth noting.