Shopify Theme Customization Needed

I’m looking to tighten up the look and conversion flow of my dropshipping store, https://nuvomart.me/. The shop already runs on Shopify; I simply need someone who knows Liquid, CSS, and the Theme Editor inside-out to make three focused changes:

• Hero section
– Replace the current banner area with an image slider. It should be fully responsive, load fast, and allow me to swap images easily from the backend.

• Product page
– Remove the existing “buy cash on delivery” button.
– Add a single “Buy Now” button in a modern, sleek style that blends with the theme. The standard “Add to Cart” button stays untouched.

• Checkout / payment logic
– Apply an automatic extra fee to Cash-on-Delivery orders.
– Offer a visible discount on prepaid methods.
– Clearly highlight this incentive on the payment page so customers see the savings at a glance.

Acceptance criteria: the slider must display smoothly on desktop and mobile, the new button must inherit all Shopify tracking events, and the surcharge/discount rules must calculate correctly in both test and live checkout.

If you’ve handled similar Shopify tweaks before, especially around COD fees or dynamic checkout buttons, this will be a quick win for both of us.