You can hide them with css:
.joms-module--toolbar .joms-js--notification-chat,
.joms-module--toolbar .joms-js--notification-friendrequest,
.joms-module--toolbar .joms-js--notification-general
{display: none;}
Don't know that template and don't have it. If it has custom.css than yes, you can add that code at the end of that file. If not add it to style.css or template.css, but bare in mind that those files can be overwritten on update of JomSocial or Socialize theme.
Creating custom.css does not guarantee that it will be loaded and I don't know for sure if it will be. Wait for reply from moderators on that case.
This template is from Jomsocial => Socialize Theme
I have this code set to "custom code" (under templates), where Dimas your colleague put another code for something else .... but nothing happens ...
Thanks