@torn2 edit the theme template to remove the link to the topic if the user is a guest so they can't get to the topic page.
Why "Moderator" can't Edit Topic of Others?
This is one of the issue I am facing, where I created a group called "Moderator" and we are not able to give any special permission to them like, editing the topic or deleting it.
In this case; the "Moderator" reverted back and asked "What special permission does he has other than general users?"
Any help on this?
Got the solution.
The option is available under Manage > Categories > Options > Access Control > Search User > Privileges.