The ticket is now balanced: cool/warm; youth (relative)/experience.  Ties to PA won't hurt but not essential.

Re strategy, I think there are a couple of good ways to go.  Biden's experience really does trump McCain's.  Subject, verb, POW; plus Biden is a lot smarter than McCain.  Also, compare Biden as VP to Cheney; Biden will be a good Cheney: Someone with deep knowledge of the political system and with a view of the US in the world that is far different from Cheney's.

Unfortunately, the campaign deal with the Republican's attack on character and strength (read: manhood) directly and without qualm.  McCain's abilities, values, and political connections must be questioned, but also his character and/or state of being; it is necessary in this political climate. 

One way may be to focus on what has happened since he was savaged in 2000 by Bush, when he complained that they know no depths, to now, when he is using the same approach.  Suggests personal ambition to be president -- which he has said in a book, I believe -- willingness to sell out to achieve it, and a false sense of entitlement to that post. 

The New Nixon won election.  The New McCain should not.