That's a lot of changes to the recipe. Remember, baking is chemistry, many of the ingredients play a crucial role in the recipe's success. Too many substitutions will yield a product very different from the original recipe. Canola oil and dry butter won't cream and make a light an fluffy mixture that's called for in the recipe, this contributes greatly to the texture. I see your changes making a very dense pie. Shortening is very shelf stable.
I'd definitely not mess too much with the eggs, they are what hold the whole pie together, help it set. I'm not sure if powdered eggs would yield the same result in a recipe like this.