I don't see any "could" indicators in the zen_products table.

The initial table (my_products_dsdi) I import my products and updates in to has columns call "SHIP_METHOD" and "SHIP_PRICE".

SHIP_METHOD can be Individual Shipping, UPS RATES, or Free Shipping

SHIP_PRICE can be 0 - whatever

I'm not sure what you are implying by "can the master_categories_id be used for this".

Thanks.