Very cool.
It reminded me, on a much larger scale, of Diane Gaudynski's sashiko quilting.
Her sashiko goes for the circle motif, while you're using the flower, but they are both created the same way.
You might want to take a look at it.
Here's her blog post from 2009:
http://dianegaudynski.blogspot.com/2...hiko-tips.html
It would allow you to do the whole quilt in lines rather than turning the quilt numerous times within each block. You wouldn't have to mark a grid because you already have one - the blocks. Maybe just mark the center of the blocks for guidance for each "swoop" in the line.
And, yes, you can continue to the whole quilt with your walking foot.
Just a thought.