OK, I have beat this team enough :P to know half of what you were running without reading it, so I feel that my input will be beneficial.
Scizor - Looks great but I am going to give you a set that I have come to know and love. Replace Life Orb for a Flying Gem and put Acrobatics over Superpower. Acrobatics allows him to hit a multitude of things that his two STABs alone can not. There is nothing wrong with your set but I think you might like this one as well.
Jirachi - Jirachi os one of my favorite pokemon, and for good reason too. Change his EVs to 252 HP, 4 Satk, and 252 Spd, and give him a Timid Nature. Now you are going to want to replace Shadow Ball and Iron Head for Wish and Water Pulse. Wish and Calm Mind allow you to stall like a baws, all the while biulding up your SAtk for a sweep. Psychic is STAB, and Water Pulse covers both of your weaknesses, as well as having a large chance to confuse the target thanks to serene grace, which makes up for it's low power.
Lucario - No. Why would you have Swords Dance when only one move in your set gets boosted by it? You should run this set given to me by Josh:
Lucario @ Life Orb
Trait: Steadfast
EVs: 252 Atk, 252 SAtk, 4 Spd
Lonely Nature
Salamence - You're doing it wrong. Get rid of that horrid Dragon Gem and slap a Choice Scarf on that sucker. Keep the EVs but change 4 SAtk to 4 Def. Next, change Dragon Dance and Fire Blast for Stone Edge and Dragon Claw. Come in late-game on a weakened enemy and Outrage, and you will PWN.
Gastrodon - I like it
Chansey - The only thing I would change is I would replace Flamethrower for Protect, but that is just me.