Joe also knows certain things, or has overheard certain things, that he keeps private until someone who is connected to said "things" pisses him off. I recall that mongoloid Greg Tosto setting Joe off, and Fosco subsequently going off on Tosto's uncle Rocky Infelice in the comments section, trashing Rocky, calling him unarguably the undisputed worst boss in the history of the Outfit. Although he's not very far off the mark there (Infelice was not the brightest crayon), it was clearly meant to trash the the former boss's name within the southwestern suburban communities in which the Infelice family resides. Fosco knows that community members/family members follow his site closely, and pride is very sacred with these people.

Sure, he embellishes once in a while to stir things up, but a good deal of it is stuff that he keeps pent up until you wrong him. That's what makes him such a nuisance.

Regarding Mike Mags & the Hatch hit, who knows. Mike obviously wouldn't have been upset about it, as it got him out of a pretty terrifying bind. Of course he was probably briefed, but that's likely as far as it went.

And finally regarding the Marcellos' relationship with the Hatch, the hatch was a complete psychopath/loose cannon to begin with, and had been really crossing some lines/pissing people off within the organization around that particular time period. I recall Little Jimmy ordering Michael Marcello & Frank Schweihs to pay the Hatch a visit not long before his murder, trying to talk some sense into him, and it not going well at all.