wrote:

This is the pacific NW so plenty of rain falls in winter, though now
it's dry 2 feet below the surface. Last winter it seemed water was
coming out of the toe about a foot lower then grade.

You'd probably want to make sure a filter fabric is behind the drainage just in
case. That will hold back the finer material and keep it from washing away and
keep the drainage crushed stone from clogging.

is a vertical fabric something like whats shown in the last picture on
this page? - http://www.millerengrs.com/rock_walls.htm

Yes. You'll see it used in a lot of places - highways construction for example
- whenever they want to drain. If you see a recently constructed rock wall, you
can often see a bit of fabric sticking up a couple of inches at the top.

I'm guessing buttressing is laying a few of the rocks perpendicular to
the run of the wall and into the hill.

Yes - interlock the rock like brickwork if possible.

how would you crib the rocks?

Sorry, I should have been clear - a crib would be made using wood or concrete
http://www.phigroup.co.uk/products/rw/andacrib.htm. Not what you're planning,
but something I consider a good idea.

Mike