Can you make one cake instead of dividing the batter in 2 cake tins?

Can I use the shortening recipe in baking recipes that require butter? Can I whip it with an electric beater while making the cake batter? It is difficult to procure xanthan gum. It is so exorbitantly priced. I cannot make vegan butter solely due to this reason.

Is it possible to refine coconut oil at home ? I do not quite like the idea of using an oil refined through industrial processes where the possibility of chemical additives being added to it are mighty high. Though freshly extracted coconut oil has a nice smell.

You have mentioned that coconut oil requires to be melted before adding it to the butter. But in Goa coconut oil is always in the liquid state, Goa's climate being tropical, except for the very brief period of winter (November-January end).

We use home made unrefined coconut oil (from coconut trees in our garden) for cooking too. Can I use home made oil? Is it ok to use it directly as melting it is not possible, unless I freeze/refrigerate it and then melt it?