[1] Li Guangbiao at the wedding and [4] Zhu Hong on the floor are premonitions/flashes of things to come; [3] Sang Zan's cave pillar is where the Awl had been

Ooh, it just occurred to me that those three are all connected to Zhu Jiu and his going after the Hallows!

But that doesn't explain #2, unless the Awl thinks Fourth Uncle is secretly in league with the SID's enemies. ;-)