Do products derived from coconut need to be kept cool

Butter, even a compound butter like this, shouldn't have enough moisture to get moldy easily. I think the issue is that you are clarifying the butter in boiling water, which could be causing pockets of moisture in the finished product. You could try melting the butter in a pan without water, adding the herbs, and then allowing the water based part at the bottom to cook off. Once that has happened, you can strain and chill the butter as usual.

I've had good luck substituting cashew cream for heavy cream in soups and curries. I've had a lot of people actually prefer it!

To make it, you follow the basic procedure for making nut milk, but skip most of the steps. Soak cashews in enough water to cover them for at least an hour or two, then puree in a blender until it's as smooth as you can get it. Add a little more water until it's the thickness of cream, throw in a pinch of salt, and you're done.

It's good for things where you need the richness of cream, but don't want other characteristics like sweetness or tanginess that other substitutes might have. I've even seen it used as the base for cheesecakes, and vegan cheeses and cheese sauces.