I'm sorry but that's not possible. There is no an easy way to do that. This requires lots of custom codding and redesigning. We'll take this under consideration for future middle version releases, but at the moment there is no way to do this.

What i wanted is edit button next to the Reply button as text "edit".

It was like that in previous version of wp discuz.

The code allows to always display the settings icon.

If you're familiar with the programming you can customize comment template files and change the design as you like. More info here: https://wpdiscuz.com/docs/wpdiscuz-7/customization/custom-template-and-style/

The code provided by Tom should be added in the "Custom CSS Code" textarea loacted in the  Dashboard > wpDiscuz > Settings > Styles & Colors admin page. More info here: https://wpdiscuz.com/docs/wpdiscuz-7/plugin-settings/styles-and-colors/#custom-css-code

And this is changing edit button visibility or last edited form?

The last edited information can be hidden by disabling the "Display comment editing Information" option. The option can be found in the Dashboard > wpDiscuz > Settings > Comment Moderation admin page.

More info here: https://wpdiscuz.com/docs/wpdiscuz-7/plugin-settings/comment-moderation/#display-comment-editing-information

Please put this CSS code in the Top Admin Bar > Customize > Additional CSS > Custom CSS Code textarea, then delete all caches:

#wpdcom .wpd-tools.wpd-hidden{
    visibility: visible;
    opacity: 1;
}