Two religious questions

Question 1: Given Calvinist theories on predestination (Summary: "You're either of the elect or you're not."), what prompted them to live a path of denial and basically no fun? Is it just a modern-day way of thinking to say "Well, if I'm of the elect, then it doesn't matter what bad I do, and if I'm not of the elect, it doesn't matter what good I do, so let's just go out and party!" I'm reading The Wordy Shipmates by Sarah Vowell, and it's basically about the Puritans, and how they thought about things, making use of their writings.

Question 2: Is it reasonable to say that the Universalist Unitarian and Ba'hai religions are essentially the same thing, just coming out of a different background? UU developed out of a Christian theology, and Ba'hai out of an Islamic one. But the core teachings seem very similar. I welcome comparisons and contrasts.

I'm opening this question up to the real world, so if you want to find someone who wouldn't ordinarily read this, feel free to point them my way...