Yeast does not die if it is frozen! And it would be nigh impossible to add salt after the dough has risen!
Julie, I bake all of my own bread (except bagels, I just cannot get those right!) and I have found that all whole wheat bread is very dense even with the wheat gluten added. I use at least half bread flour, the the other half wheat or oat or whatever (adding wheat gluten, too).
Try white whole wheat flour-- it has the same fiber/ nutrients as regular whole wheat but is much finer in texture and makes a lighter loaf. Also a tablespoon or two of olive oil per loaf makes the finished bread moist.
Good luck-- practice makes (close to) perfect!
Can't you just eat what I put in front of you? Do you have to know what it is?
Ria Parkinson, Butterflies (BBC, 1978-83)