Curious if I can attach a given moodlet to a property (Beautiful Vista, etc.) I build or is that hard coded with "factory" created lots?

The "beautiful vista" moodlet is assigned to a lot in Create a World, so you'd need to take the world into CAW to add it.

For other moodlets, it would help to know what you're looking for; you might be able to impose some of them. For example, I believe a sim should get the "creepy graveyard" moodlet at night when on any lot that the game sees as a graveyard, unless of course the sim is brave or maybe an occult.

Exactly. And thank you.