Scott,
Thanks for explaining how you handle projects. Our definition of a project appears to be the same (The DA definition you give). I think the main difference is that we have very different work streams. I'm a professional too, but I have relatively few things that just appear during the day compared to you. It means that I have to recognize and plan a lot of projects or I just plain wouldn't accomplish very much. Instead, I'd sit in meetings half the day, and do the enjoyable parts of my job, instead of all of my job, during the other half of the day.
Also, I like to keep Projects active even if I may not get to them during the week. They are not Someday/Maybes because I really want to get them done, but instead of having a Not This Week category, I like having their Next Actions in my context sensitive lists just in case I get a chance to work on them. For instance, I completed some of my non-strenuous @Home Next Actions yesterday (Sunday) because I was too sick with a cold to go out and do anything, but too bored to do nothing. Keeping lots of projects & Next Actions on my lists also helps me get a lot of little errands done when I just happen to be in the right place to do them, and since I travel a lot, a spare hour in an airport can be a great time to check my @Anywhere list.
In many respects, I think these differences show one of the greatest strengths of GTD. It is truly a flexible system that can be applied to virtually any kind of work and life.
Thanks again,
David