Maybe, maybe, you should replace either brave bird or fly, depending on what you prefer (recoil for greater power or free recovery) because it always is bad to have more than one damaging move of the same type.
I dislike your Serperior moveset due to having 3 moves of the same type. I know that Serperior's moveset is very very limited and my own Serperior's moveset is pretty bad. But maybe try to change something.
You should replace Simipour as there are many other Pokémon who can do his job much better than he can do it. Replace Surf for another attack and maybe Ice Beam for Ice Punch for his nature. Give him a sitrus berry to compliment his ability. My Simipour is a HM slave :D (Surf, Waterfall, Cut, Dive)
Sawk... Get rid of Low Sweep. I use my Sawk as a payback killer with endure and mold breaker.
Your Gigalith again has two damaging moves of the same type. Change something here. Maybe Return, I don't know honestly.
What's with the question mark next to Alakazam's name? His moveset is ok!
Overall, try to get Pokémon with good natures (I play my Pokémon games in German so I don't know most English nature names) and replace all the items that only power up moves of one type with moves that either power up all moves of a kind (muscle band or wise glasses) or choice items or shell bells/leftovers.