Single Wall in the attic is ok right?
Single wall is allowed in many locations, as long as the proper clearances are met.
However, a vent routed through or in the attic must be B-vent (in most jurisdictions).
I know Dom, I mostly posted this because as I recall a guy had this in his report as ok and he won some sort of report shootout here a while back.
Hard to tell from the pic but the single wall flue (in the attic) appears to be too close to the plywood roof sheathing. More concerning is the vent connection in the 2nd pic, it appears to be loose, not inserted all the way and no visible means of fastening.
The entire thing is wrong. Too close to everything, not securely attached, single wall in attic, made of asbestos… yada yada yada.
Second pic looks like possibly air-cell insulation (asbestos) going into and through attic?