Yes, you can! I would freeze in a ziptop bag and use within 3 months. When you thaw, you will want to let it come to room temperature and you will want to remix!

Yes! You can use King Arthur’s here!

Hi! Here is my post on how to heat-treat flour: https://cookiesfordays.com/how-to-heat-treat-flour/. It sounds like it is similar to your method, I just typically treat it in the oven or the microwave.

I have never tried this recipe with coconut cream, but the purpose of the heavy cream is to help bind and thin the frosting out a bit so coconut cream as a substitute should work!

Yes, you can use milk in place of the heavy cream! You will just want to reduce the quantity by a lot because milk is so much thinner than heavy cream.

You should be able to frost about 12 cupcakes with this recipe as is!

If you are lightly frosting your cupcakes, you will be able to frost about 18. If you are piping it on generously, you will get about 12!

Yes, you can! This will last in the fridge in an airtight container for up to a week.