Hi,

Thank you for reaching out to us.

1. Kindly be advised that our Metronic Asp.Net-Core version is a Starterkit based on the HTML version. This version contains a fully functional layout along with a few pages for a quick start (New Password, Reset Password, Sign In, Sign Up, Default Dashboard Page, 500 error page, and 404 error page).
   
   You can easily add any other pages by referring to our HTML version, all JS, and CSS code required for any page is already included in our Asp.Net-Core Starterkit, all you need to do is just copy HTML markup and include JS file on your page (if it is required).
2. Mode switcher menu is included in the default Metronic package. Please refer to file Starterkit/Views/Partials/ThemeMode/_Main.cshtml
3. We do not have a separate version with square boxes but you can easily change the border radius for all elements by updating variables in demo31/src/sass/components/_variables.custom.scss.
   
   To have fully square elements change all border values to 0rem.
   
   
   copy

   // Border Radius
   
   $border-radius-sm: 0rem;
   
   $border-radius: 0rem;
   
   $border-radius-lg: 0rem;
   
   $border-radius-xl: 0rem;