Hello Milan,
I am really sorry for the delay of this reply as it is a weekend for us here.
Can you try open this file and add the following code and see how it goes?
JoomlaFolder\components\com_easyblog\themes\dashboard\system\dashboard.write.options.php
//LINE 193
<li>
<label><?php echo JText::_('COM_EASYBLOG_DASHBOARD_WRITE_CREATION_DATE'); ?> : </label>
//LINE 213
<li>
<label><?php echo JText::_('COM_EASYBLOG_PUBLISHING_DATE'); ?> :</label>
// LINE 232
<li>
<label><?php echo JText::_('COM_EASYBLOG_DASHBOARD_WRITE_UNPUBLISH_DATE'); ?> :</label>
// ===================================================================================
// 3 above LINE i mentioned you have to add style="display:none;"
// Example
<li style="display:none;">
By the way, "Send mail notification button" send mail to whoom - to user or to admin?
>> This is depend on who is the author of this blog post, if the author is admin, so the email notification will send to your user.
>> You can look for the setting from your backend > Easyblog > Setting > notification.
2.
It seems that the hack won´t have long life. With the next Joomla update will the fille be overwritten. Isn´t there any better solution for the code placement?
>> Yes, you have to backup on this file for every time update in the future. Because all the option is define on <li> html tag, it will not able to hide it use in CSS.
Create date
Publish date
Unpublish date
Hope this help.