Joseph, you asked about deleting a comment. You should see a "hide" button on your own comments, and you can hide them but not delete them. (I will tell you that once in a long while, a G2G moderator may come along and "unhide" a comment. However, you can hide it again, and if you wish to, contact the moderator to explain.)
You can not delete other people's comments. If a comment is inappropriate or highly offensive, you can flag it. If a second person flags it, then it will be hidden. (If you flag something by accident, or then change your mind, it is just as easy to unflag it, using the same button.)
I hope this is helpful.