Here are some elements of answer, do not hesitate to use the search function cause it's a common question .
- For the product code display, just activate the option in System>Configuration>Display>Default parameters for products ("Display product code")
- For the price, I'm not sure what you want but take a look at the listing_price view of product to add a <br/> and take a look at this class 'hikashop_product_price_main' for adding css rules
- For the pinterest button, something like that should do the job (once again, you can spot this by yourself thanks to firebug or code inspectors)
#hikashop_social_pinterest{ margin-left:-10px; }
it will in this case move the button 10 piels on the left
- And I didn't get your first question since the product code doesn't appear on category listing