Re the turtle hatching: My sims live on Mua Pel'am. And yes, I've checked all the beaches constantly after the message and nothing.
And I just removed all my mods, brought up an old save and played with a townie. Had her in the water for nearly 3 days. She had fin fear several times but I never saw any sharks or fins. And she didn't get eaten either, lol. The latter being good, because I don't want any of my sims to be eaten, but I kinda would like to see sharks.