Re: Walking Up Hills
Dropping into a walk can often mean that your heart rate lowers as you go from a more aerobic to an increased anaerobic state, as you use more power. That's why the change might feel easier. (For a while anyway until you then start to push towards your limit to process lactic.) If working hard aerobically suits you then keep on walking but limit your stride length so that your heart rate stays higher. If you've got legs like Chris Hoy then you'll have the power to stride out!
As far as etiquette goes, just be firm but fair. If you can get past someone without elbowing them in the head then go for it, otherwise wait for a wider bit. As far as enjoying the view goes though, when I'm walking it tends to be the patch of ground just in front of my nose, or at the very most the heels of the runner in front!
Fitness can't be stored. It must be earned over and over, indefinitely.