I can't help but notice that you only have 5 pokémon. Are you planning on using this team in competitions against fellow human players? if so, you should probably get a sixth...but be careful. You've managed to avoid having any 3x weaknesses, but you have six 2x weaknesses. Your sixth pokémon shouldn't be weak against electric, fighting, flying, ground, psychic or rock, because if it's weak against any of those, then that type will deal super-effective damage to half your team. That's a weak spot you don't want.
You should definitely replace Slash on Slaking, simply because there's no good reason to have both it and Return except PP management, and that only applies in-game. You don't need our help in-game. Also, Togekiss's Fly is okay in-game, but a big no-no in tournaments. You're handing your opponent a chance to switch to something, like Skarmory, that can laugh at a Fly attack. Unfortunately, I don't have the tournament-level knowledge to suggest something better. Someone else will probably reply to this thread with a more thorough review.