Use this CSS code: 

:hover::after {
    display:none !important;
}
:hover::before{
    display:none !important;
}

How can i remove all tooltip mobile and desktop.

We don't recommend adding extra padding for those replies. The screen of mobile don't have big widths, so you may have issues with the design.

Please watch this video to better understand what I mean: https://www.screencast.com/t/pLgwdcBPgj

Anyway, if you still want to add extra space use the CSS code below

@media screen and (max-width: 600px){
   #wpdcom.wpd-layout-3 .wpd-reply {
       margin-left: ***23***px;
   }
}

Put the code in the "Custom CSS code" textarea, located in the Dashboard > wpDiscuz > Settings > Styles & Colors admin page.

Please change the red-marked value before using it. 

Don't forget to delete the caches before checking.

Also, please try in incognito mode if you're checking on mobile devices. Because mobile browsers have a hard cache, you'll not be able to see the change immediately.

however when it comes to mobile all the replies will be in the straight vertical line. no way to find who reply to whom. how can i fix that.

We don't see the wpDiscuz installed on your website at all. 

also can you please tell me how can i get the layout which you had in wpdiscuz 5

You can downgrade the wpDiscuz to version 5.X.X and use it if you like its design.