I would recommend not having two separate calendars for your hard and soft landscapes. I originally did this and discovered that it taught me to treat my Calendar as a someday-maybe calendar -- to think of things as written in sand until they turn into stone. But this turned out not to be a good thing for me because I started treating all of my events as "optional."

What I've done instead is keep one calendar in iCal called "Hard Lines" -- where I keep only things I'm definitely committed to. This keeps me from treating my calendar as a someday-calendar. It's been difficult, but forcing myself to treat my calendar as something written in stone rather than sand is key to really getting the calendar-component of GTD working properly.

But, I also noticed I put a lot of "reminders" to myself on my calendar. They are not hard lines, but recurring things I need to be reminded of on a particular day or month or weekly or monthly. iCal is nice for setting recurring reminders, so it makes sense for me to use it this way for items that are not necessarily events and not necessarily tasks or projects (e.g. eat lunch at noon every day, turn your computer off at 7pm so you can spend quality time with the family, try to eat more low-glycemic carbohydrates throughout the day, etc.)

On Getting a List of One Calendar in iCal:
I don't know that you can just create a list of events from one calendar on the fly in iCal, but you can choose "Print" and select only the calendar you want. So that might be one workaround. But seeing a list format of all events without having to do a search would be nice. Perhaps Apple will add this to a future version of iCal?

Todd V