Girafarig: Give it Specs/Scarf and give it the set HP Ice, Psychic, Thunderbolt, and Energy Ball/Shadow Ball.
Mightyena: Not much to say about this guy....I would replace it with Simisage because it has access to higher-power moves. And its movepool, I think, is a tad bit bigger.
Simisage @ Choice Band/Muscle Band/Life Orb/Flying Gem*
252 Atk, 252 Spd, 4 HP
Let me know if you want a special set.
Beedrill: Ok, I guess this can work. But why Agility? You already have the reliability of a Sash. Go for X-Scissor(STAB), Return (Power hit), or TwinNeedle (Extra crit chance, STAB)
Seviper: I suppose you could keep Bulldoze......Maybe you could fit Glare somewhere in there? Your decision what to do, man.