Note re:Snap.svg. It's an excellent library, and I've just started playing with it (you can morph with it!! :D ), but it's minimally documented (the API fully is documented, but it's very thin on examples). If you end up having trouble making things work, check out Raphael.js . This is another libra...

I realise this question was posted a long time ago, but for the benefit of those who arrive here courtesy of google: I've found that you can reset the rotation centre with the XML Editor (Edit > XML Editor). Find inkscape:transform-center-x and inkscape:transform-center-y , and set them both to zero...