How about this for a possible dynamics interface: http://www.tomlechner.com/randompics/finishing.png
If you start with a blank strip only those settings you change are applied. If one node has a setting changed, and another doesn't, then interpolate with the object's original setting. Perhaps hover or double click over nodes to pop up an info box with what settings are changing, perhaps also allowing to toggle whether that node affects those settings (or have toolbar for that if you insist).
If you want to use different grid systems, they could be variations on the bilinear option, but editing those would be a task in itself! Perhaps in the short term, just have an option to apply different grids available to only scripting?
It's common to want to randomize within specific bounds, maybe instead of dragging the marks themselves, clicking on a randomize mark could toggle visibility of a randomize boundary.
A downside of this is that it stuffs a ton of possibly unrelated styles into the same nodes. Many times this would be ok, but one might want to stack strips instead.
-Tom