[quantumhobbit]

Chaotic rotation occurs primarily in bodies that are not spherical. These tend to be smaller, because gravity forces larger bodies into spheres, and would have a thinner atmosphere if any due to the small gravity.

Not saying life is impossible on such a moon, but it would be even weirder than just strange day night suggests.

[mkirklions]

But wont millions of years of chaotic rotation cause a large body to become round?

Thousands of years this sounds realistic, but remember the scale of things is in billions of years.

[lainga]

I believe the chaotic rotation would stop as soon as the body became round, to conserve angular momentum.