While i also feel that Groundon is a bit out of place, your team is not exactly a weather based team, so i guess you can keep it.
I don't know which pokes you're planning to hit with Grass Knot though. I'd run Mewtwo Y with Aura Sphere. Maybe Thunder if you're planning to get rid of Groundon.
Kyogre, Arceus and Xerneas look good enough. Although:
She gets it. That's more of something personal, but i wouldn't use it on anything.
As for Zekrom, i would never run both Fusion Bolt and Bolt Strike at the same time. I'd keep Fusion Bolt since the CB makes up for Base Power difference.
And keep in mind what Murdoc said: I don't see what you can do to absorb status. I think you should work more on that.