Sorry Candy I didn't reply sooner. Had a busy weekend. Anyhow, I think you got your answers. I really believe that liquid is the main thing that makes a cookie soft. And liquid can be found in brown sugar, eggs, and fat. I believe if you use Crisco shortening, which is zero water (if I;m not mistaken), it may help a lot. However, the taste will be compromised. So perhaps, you should use half butter, half shortening. And also, the baking time is another contributing factor. Like when you make biscotti, you have to bake it really long to dry out the biscotti....so perhaps, if you bake it a little longer, it might help too. I think the way a cookie turns out is dependent on a lot of factors (and weather being one of them). So here's my 2cts worth: Cut down to one egg, 1 c sugar and 1/2 c brown sugar instead of the other way round....and since the liquid is lesser, don't put in the full 2.5 cups of flour. This is what I usually do...perhaps that's why my cookies always turn out crispy. I also do most of my baking in the winter.
I hope this helps. Keep us posted about your cookies. 8)