Bob,
you have a lot of control from the seat of how aggressive
the blade is.
depending on how low your shoes are, you should be able to control
the angle of the blade with the curl function of your loader.
use the shoes as a pivot point, and by using the curl up or
down you can push that cutting edge down closer to or
into the dirt. (theoretically)
a soft base, not frozen, will wreak havoc no matter what you
do. we had warm days and inches of rain this past weekend before
our 2' of snow, so all the snow that fell in the early part of the storm
landed on warm wet ground and made it quite challenging for everybody
to move. it was basically slush at the ground with 2' of snow on top!
i would imagine you want the springs somewhat tight, so they need a bit
of pressure before the blade trips. but you really want the edge gliding along
just above the gravel so it doesn't, a tricky feat that will come with experience.
many blades have a lock feature that allows you to make the blade
rigid, like for dirt work, i can't remember off hand if the curtis has that
or not. you can look and see if there is a pin or holes for a pin that would
do that. keep in mind with it rigid, it's gonna bite, and bite hard if you do
end up into the gravel.
keep us posted on your progress, lots of good info here at TBN!