<dsp:valueof param="product.displayName"/> should print your product name. if it is not, then check:
-you are able to show all entries in ACC
-check if you are able to print catagories-
-check if product name parameter that you are passing from category page is same as in product page.
-check if SKU name parameter that you are passing from product page is same as in product page.
In InventroyLookup we are passing sku.repositoryId:
<dsp:param name="itemId" param="Sku.repositoryId"/>
<dsp:param name="useCache" value="true"/>
Stock Level :<dsp:valueof param="inventoryInfo.availabilityStatusMsg">unknown</dsp:valueof>
In below documentation it is given during adding item to order also we are setting sku.repositoryId:
Is there any difference between Sku.repositoryId and Sku.id?
Most repository item descriptors shipped with Oracle ATG contain a property descriptor that names the item's ID. Having a named ID property is not a requirement. The repositoryId syntax is provided to allow application code to refer to any item's ID, whether there is a named property or not. When there is a named property, there is no difference between using repositoryId or using the name ("id", in the case of sku).