New module or template file edits for extra functionality to colour swatches module

I require either a new Magento module creating, or direct template file edits to add the following features and fixes. I need to know which files have been edited if editing template files so that they can be backed up and replaced when updating modules etc. The features that I would like adding are: 1. I have created a "More Colours" label that is shown above the colour swatches on the category page but it shows on every product currently. I would like it so that only if there is more than one colour/associated product, then display the "More Colours" label and the swatches. If there is only one associated simple product (colour) then do not show the label and the swatches. You can see what I mean here: [login to view URL] 2. When clicking on a swatch in layered navigation for either the "Colour" attribute or the "Lens Colour" attribute, change the main product image to the corresponding colour's image on the category page. For example; on the following page, I have selected the attribute "Colour" as "Black" but the products "Balenciaga BAL0093" and Balenciaga BAL0150 are showing the images of the "Silver" colour option instead of the black colour option. I need the main image to change depending on the colour swatch that is selected. This is for the category page only. https://www.primeoptics.co.uk/glasses/#frame_colour=black&gan_data=true 3. Currently, when a customer is selecting options on the product page, if a required option is not selected but the customer then tries to add to cart, a pop up should show alerting the customer that required options have not been selected, but this is not happening. I need this issue fixing so that the customer is alerted that they have not selected a required option. You can see this issue here: [login to view URL] The issue also exists on the checkout page but I assume that when the issue is fixed for the product page then hopefully it will be also for the checkout page. This is a live site (not many visitors though) so quick work with minimal disruption is required. If possible, I would like this done without conflicts or edits to any existing modules so that future module updates are not impacted. If edits to existing modules are required, then would need to discuss with me before proceeding. Potential for ongoing work in the future, if I am happy with the level of knowledge, communication and quality of work. Thanks