Do the alternative suggestions help? Yes, to an extent. The do take a bit of the edge off, even if it seems insanely miniscule. They also mean that those few minutes that are spent doing those other things are minutes you are not cutting.
Do the urges decrease with time? Yes, to an extent. I didn't see any real improvement to urges until I had been clean for about two years. And like you said everything was a trigger. My pencil, pen, staplers, scissors, kitchen knives, candles, the list truly is endless. I couldn't even use those visualization techniqies of imagining you are on a beach or in your favorite place because I was instantly drawn to the triggers there. I didn't feel safe form myself anywhere. After a couple years I got some relief when I was in teachers offices, where I felt it would be a betrayal to cut because it was their space. And I didn't crave every second of everyday. Backtrack to the first few months I had quit, I spent every night puking my guts out till I didn't have the energy to get pills so I wouldn't attempt suicide again. I couldn't use scissors or knives in the kitchen. Some days were so triggering I had to completely stay out of the kitchen and not let myself be alone. Sorry, I'll have to continue this post later, kid just puked everywhere, back to mom duty.