No those are all lies. There is no code that could make you Pokemon or your egg that hatch to be shiny permanently.
You have to walk around with it. It will hatch faster if you have a Pokemon with the ability Flame Body.
you run around sinnoh and it will hatch.
You run or bike around.
pure luck
no
you need to hatch a togepi in soulsilver or heartgold then trade it to pokemon diamond
run around
Yes
you walk around for ages and ages and it will eventually hatch
Unfortunately, I doubt there is a cheat that would do that, but, if there was one go to http://www.supercheats.com
in Oreburgh city in the museum
you can't hatch a pikachu egg on diamond, it hatches in to a pichu.