I have one question about Swords - why you prefer StP over PtE?
That's a tough question, but frankly one I don't really have to address. I run Diabolic Edict in the GWB version. The main reason for STP instead of Path is that I've been running Swords and I've never wanted it to be Path. Will Path sometimes be better? Of course. Will Swords sometimes be better? Often. The life gain is not negligible, but you reallly don't want to give your opponent additional mana either.
In my experience, decks with 5 Waste/Strip run plow over Path without exception.