blazed You would get a new product_id number which would then reflect on search engine index's. (ie you ranking in search engine results for that particular product).
As Schoolboy says just use 1 / 0 if you are regularly updating products, only use 9 if you never would have that product in again. By disabling the product this should not effect your shops speed and this product would not show in the cart if disabled.

LovejonesBoutique Did you enter a product manually in ZC first ? as if you uploaded via EP first, your products will not show up. I haven't done this myself but you might try 'Reset ALL Products Master Categories ID' in Store Manger.
From my experience you really want to put your images in separate folders and you can control this easier if you have hundreds of images.