Edit my Shopify theme code (continous project). Add functionality.

We are improving our Shopify store [login to view URL] In this project, I will need your help NB! Don't write me if you cannot handle the job! Don't offer your services if you have not checked the website, and screenshots - then you will understand, what is needed from you. Project description: Change our product pages structure: 1) On the pictures please add the buttons that will help choose next or previous pictures 2) Add Warranty Tab (we must have option to edit text well) 3) Make reviews underlined and clickable - after click, it must activate tab "reviews" and go down 4) Additional edits according to the file (ask additional questions, if needed). "Play video" must activate video with the youtube url we choose. Example product page url: [login to view URL]