Wordpress Template Modification & Admin Dashboard Creation & Notification System

Hello, I am currently using the theme "mylisting" with the 3 column layout. [login to view URL] 1. I am using the "cover image" for the preview card. My images are 300x200. They are blurry and cropped due to the 3 column layout. I would like 4 columns in desktop view, instead of 3. Please edit the child theme to enable this. 2. I would like to pre apply a filter whenever the explore page is viewed. This is not a standard feature but the developer let me know it could be added by a 3rd party. The filter to be applied is to exclude listings with a "Status" of "sold". I want "sold" listings to be hidden by default, but still available if the filter is removed. 3. The theme offers a "direct message" functionality between buyers and sellers. The administrator does not have any oversight into ongoing conversations. We would like to know when leads are being generated on site site. We would like an administrator dashboard to be set up that shows all ongoing direct message conversations, shows total number of active listings, total number of pending listings, and total "asking price" of all listings. 3. I would my users who have "saved" listings to get email notifications if the "asking price" changes. 4. I would like users to be able to submit a form telling us what types of trucks and features they require. They will get a notification when a listing matching their criteria becomes available. They should also be able to manage their queries from their dashboard in a section called "New Listing Alerts".