Little prestashop edit

Hello, I need to solve 4 little things in my prestashop installation: - Remove the header scrolling from display resolution under 1024px - Remove the Ajax cart and when click on cart icon open the resume page - Fix a little problem with filter and category page (the url are present but don't work when click on it) - Fix a little problem with a imported products, practically when I import a product and create a combination, the combination appear in frontend but don't work