Cole and Phoebe didn't meet for the first time on her college campus, they met the previous night.
When Coop and Phoebe go to the past to Dex, he's watching a different program on TV than he was in 8.5 (Rewitched). Dex was watching a news report with Agent Murphey when Phoebe showed up to tell him about herself, not a report on the Golden Gate Bridge.
At around the 12 minute mark. Billie and Christie are talking about going to meet their parents. Christie's hair moves from in front to behind back and forth.
Phoebe shows Coop the final time Cole was vanquished. This happened in an alternate reality that Phoebe has no recollection of. Paige was the only sister that was involved and remembered it.
Coop thinks that the only demon Phoebe has ever dated is Anton (from her past life), but Cupids are supposed to know all details of their "charge's" love lives, as proven by season 2.10 (Heartbreak City).