One of the things I really liked in WFRP 3ed was party tension track. Has anyone tried to convert it for Edge? I'm too lazy to get down to it, but would love to use it.

For now we're using a different solution (one of my players suggested it) - when there is tension in the party, the GM may convert one white Fate Token into a dark one. When the party cooperates nicely, achieves a small success etc - he may convert dark side fate into white.

Still, I liked the idea in WFRP that players could decide what kind of party they want and get small bonuses for sticking to the theme...

I would think as the GM you could just do that without a codified system.

This is somewhat built into the Obligation rules in the form of a strain threshold penalty. You could certainly adapt that mechanic to fit your needs.