How do I get the module to look right and integrate correctly on my custom theme ?
This is a common problem between modules and themes, and not just on PrestaShop, but on any Open Source software, even Wordpress.
PrestaShop module developers are required to test their modules on the native, standard PrestaShop theme, on all versions which the module is indicated to be compatible with (1.5, 1.6, 1.7 ...)
Conversely, PrestaShop theme developers are only required to test their theme with the native PrestaShop modules that are packaged with the main solution.
Though we understand this may be frustrating to you as a merchant who just wants for things to work so you can focus on your business, it is unfortunately simply technically and physically not possible for module developers to make their modules compatible with the thousands of custom themes out there, and vice-versa.
PrestaShop Addons' Legal Terms and Conditions do not provide any sort of warantee for this.
Refunds on a module will NOT be granted for integration problems unless the module proves to have display problems on a NATIVE, STANDARD PrestaShop theme without any modifications.
Free help for integration problems by our technical support team will be limited to telling you which CSS files and .tpl (template) files in the module you can modify, and, eventually, we may name a few CSS classes in particular you'll want to work on.
WE WILL NOT PROVIDE MODULE CUSTOMIZATION SERVICES TO ADAPT OUR MODULES TO YOUR THEME, EVEN IF YOU OFFER MONETARY COMPENSATION. WE ARE SOFTWARE PUBLISHERS, NOT A WEB AGENCY.
However, we can recommend our Web Agency Partner, Profileo, who specializes in these kinds of interventions as well as other webmastering services via their Profileo Live Business Unit. You can buy webmastering tickets from them at a price of 70€ per hour, tax excluded, which is a very reasonable rate, at least in France. You may contact them directly by e-mail at firstname.lastname@example.org.
Thank you for your understanding.