> but can go very wrong if not careful

This is vague and doesn't explain anything. Can you share any references that communicate what you're thinking about?

Unless you have specific issues, creatine is pretty easily excreted in excess, unlike fat-soluble vitamin D.

This doesn't mean you can just pound it, but for the most part it just becomes waste product.

Craze? People have been taking creatine for decades. It's really well studied and is quite safe.

You definitely want to take breaks from Creatine. It’s not something people should take year around.