I have problem with column alignment in cover row. I put video as the backgound of the row and I checked equal height of columns. Inside is 1/1 column with centered content but everything is shifted to the left. If I put margin of the left to center everything it looks wrong on the mobile version.

Other problem I have with Placeholder Image. I put it because video doesnt apear on the mobile version, but in the pc version the background starts with this picture instead of video, how can I remove this effect?

Thank you in advance. This is link to the website: https://www.sicilyparagliding.it/

Strange effect indeed (for the left shift), can you please send me a user/pass in a private reply so I can take a look please?
As for the fallback background image – this is the way the things work in the plugin, if you wish you can force that element to have no backgound for large screens (I can try and do it once I have the credentials for you).

You are good to go, I changed some of your row settings to fix the first issue, and added a custom CSS to the page for the second.

       smoothScroll.init({
		selector: '[rel="smooth_scroll"]',
		selectorHeader: '#header.sticky_header', // Selector for fixed headers
		speed: 500, 
		easing: 'easeInOutQuart',
		updateURL: false,
		offset: -238,
	});

and here:

       var options = {
		speed: 800, 
		easing: 'easeInOutQuart',
		offset: -238,
	};
        smoothScroll.animateScroll( null, window.location.hash, options );

Dp a hard refresh and tell me if all is looking good now.