Hi,
1. In order to change the description of the payment methods, you can go in the menu System>Payment methods, edit your payment method and change the text in the description there.
2. You can disable the footer display by turning off the "Show footer" option of the Display tab of the HikaShop configuration.
3. In order to change the size of the main image of the product page, you can change the options "Product page image width" and "Product page image height" of the Main tab of the HikaShop configuration.
4. In order to change the size of the small thumbnails on the product page, you can modify the CSS of HikaShop as explained here:
www.hikashop.com/support/support/documen...ling.html#thumbnails