The idea for the team is great and I really enjoyed playing it.
I've tested this team a bit and I really like E-Belt over Life Orb on Genesect. I understand that the extra damage is great but you can potentially get LO stalled which is problematic. For the most part you're going to hit what you need for SE damage and if you dont, well I don't think LO would do significant damage to where it would matter.
Additionally, I'm not sure why you want to get the surprise kill on genesect with Scarf Rachi. Genesect is great set up fodder for a lot of your team members and if you replace fire punch with u-turn, you can use Jirachi to gain a lot of momentum. Usually it's just waiting for your opponent to bring in a pokemon that walls it (early/midgame) so that you are forced to either sack something or take heavy damage. Jirachi is great late game, but u-turn would definitely help you maintain momentum and put a lot of pressure on your opponent throughout the match.
My youtube channel
[Pokemon Narrations, Let's Plays]
VM me for OU/UU rates.
wish i could change my username to chimpact :[