You can modify on this file.
JoomalFolder/components/com_easydiscuss/themes/wireframe/comments/default.php

I moved the button. But the first comments are hidden. And how to make the last comments invisible

If revert back original code, the first comment will appear when click on load more button?

Is there any test site I can test on it? because i was unable to replicate this.

And how to make the last comments invisible

This one you have to customise on js part.
JoomlaFolder/components/com_easydiscuss/themes/wireframe/post/default.js

Hi Albert,
If you want to display old comments first, then load more loads the newer comments, then you have to hack the following file: JoomlaFolder/administrator/components/com_easydiscuss/models/posts.php(http://take.ms/vdVqX)
For the js file, this should load the comments at the bottom(http://take.ms/CongC).

These changes are not protected from future updates/installation. Also, do take note that we do not support customization request.

I wanted to make comments looked like in EasySocial. But I failed to do it. And it is possible to integrate comments EasySocial in EasyDiscuss ?

Currently that was not possible to integration with Easysocial comment in Easydiscuss.

May be a component Komento can be integrated?

Currently we do not have plan to integrate with Komento comment system in Easydiscuss, perhaps you can add this feature request into our forum here https://stackideas.com/forums/komento/feature-requests .