The biggest problem that would present is one of logistics. Because of ballot deadlines that vary by state (and some states may have started mail-in voting already), we could very well have a scenario in which a hypothetical "Edwards-Hillary" ticket isn't even eligible to show up on many state ballots.
Now take this one step further. Even if they were able to get on enough state ballots that they could win 270 electoral votes, how many swing voters across this country are going to vote for a candidate that isn't on the ballot in a number of other states?
You are correct. There will be no Torricelli switch-er-ooo. The RATS are stuck with this dud.
Everybody can calm down on the swifties being able to air ads through election day. 527 or not, the swifties do not endorse any candidate and are therefore exempt from the entire campaign finance nonsense.