re: If you quickly walk 6-8 miles a day would you consider that a worthy work-out?

Are you doing it all at once, or spread out over the day? If the former, it's a decent workout, especially if it also involves some lifting, as you say.. If the latter, you're clearly way better off than sitting in a chair all day, but it's still not much intensity. Do you break a sweat, or get your heart rate up?

I'd call what you're doing a decent base to start with, but you need to find the time and motivation to do something to raise the intensity level. The good news is it shouldn't take too much with what you're already doing at work. If you can get in a hard 30-45 minute session two or three times a week on top of that, you can be in really great shape.