Hello,
I review your features list and much comfortable to provide all requirement according to you such as home page, live chat, Inventory Management, Product Listing Dropdown, Product categories, responsive, etc.
Technically, I have expert in theme design and customization, app integration, add new features, custom code, shopify liquid, bootstrap, HTML, css, javascript, ajax, json, jquery, etc.
It would be great if we can discuss further regarding job so that we can take the next step.