That seems like overkill to me..... especially the shaft seal. Gaskets usually only start to leak when there have several occurrences of disassembling and reassembling, or when you have opened and closed the strainer cover several times in a year. I could see the strainer basket cover gasket needing replacement periodically (maybe in a year), but I doubt that the rest of the gaskets need changing that often. Obviously if you notice a leak, replace the gasket immediately. Personally, I usually can go a few years before replacing gaskets. You can help your strainer basket cover gasket last by applying a thin coating of silicon grease to the rubber each time you take the cover off.
