Yes, you can.
shortening is like butter 1 cup of shortening is equal to 1 cup of butter
yes you can and it wont change the cakes in a bad way
No, syrup is sweet and oil is not. They do entirely different things in a recipe.
Swirl method is the method I would use to ice cupcakes with fondant with butter creme.
Without a doubt. Always use butter
Peanut butter cupcakes can be topped with many things. Chocolate icing goes well with peanut butter. Small toppings can include mini chocolate chips, caramel or honey drizzle, mini Reese's peanut butter cups, or sprinkles.
cupcakes
You should use the same amount of butter. It's probably also best to melt the butter so that it combines well.
Yes, but you would have to use a substitute ingredient or esle the cake would be too dry and floury to eat.
Yes, you can. There are recipes for oatmeal cookies that call for vegetable shortening instead of margarine or butter.
You can substitute with margarine, but other then that no.
In "Number the Stars" by Lois Lowry, the pink cupcakes lacked butter due to wartime rationing. Butter was considered a luxury item that was difficult to obtain during the period the story is set in.