lcooper, I kinda doubt you are doing anything wrong, your film/developer combos sound quite standard. I doubt this is an issue of scene contrast. And I agree that if darkroom contacts look good without any major grade changes then you're good to go.
Now, even if your negs are optimal, when you scan, you'll probably need to apply some levels adjustment. When you scan, do you see an option to do levels adjustment? Note that this is different from curving, which is what you'd do to raise/lower particular tonal values. Levels adjustments set the high and low levels and the midpoint; typically, in your scan software you see a graph and you have three sliders beneath it, and you move those to set your levels. You might read up on this; some useful terminology that comes up in this contaxt is the white point, the black point, and the grey point. The software I use automatically determines levels, but I usually tweak them according to how I plan to print. And I do my curving after I get a good scan with nothing blacked or whited out. No reason to clip your neg in the scan.
I'll just add that if you do plan to scan routinely, rather than do darkroom prints, then you might consider some other film and developer options. Chromogenics are quite nice for scanning, and staining developers as well. Most conventional film/developer combos just don't scan particularly well, and <beginning of mini-rant> some people make harsh judgements about the capabilities of film based on their inability to execute a good scan <end of mini-rant>...
Now, you may well eventually conclude that you'd get more suitable density in your negs by rating them a half stop or so slower box speed, but still, at box speed and with standard development, you should get okay negs.