Check my YouTube minimizer script. It removes the comments and related sections and centers the
remaining content.

This will override the mouse left click and put it in the clipboard.
You must put // @grant GM_setClipboard in the userscript configuration.
Here is the code!

var x = document.getElementsByTagName("a");
for( var index = 0; index < x.length; index++ )
{
   if ( x[index].getAttribute("href").indexOf('magnet:') != -1 )
{
   x[index].addEventListener("click", function(e) {
     e.stopPropagation();
     e.preventDefault();
     GM_setClipboard(x[index].getAttribute("href"), "{ type: 'text', mimetype: 'text/plain'}" );
   }
};

Good Luck! If you have any more questions let me know.