This Pokemon is a Great Special wall, but it should not be the lead. Even for in game Story mode, this guy could be set up on and/or preyed on by Physical attackers (Lax Aint Got Da Defenses). I would suggest a Curser set with a ChestRest strategy
but for your approach,use this moveset
What a good choice. Great Physical Attacker. Just dont use your set; it is completley walled by Poison type, and Mind Reader+Dynamic Punch is a bit Gimmicky due to Brelooms low defenses.
• Drain Punch
• Seed Bomb
• Spore / Swords Dance
• Thunder Punch
Not much to say about this guy; I dont know much about him. But based off of my experience in RU, he could benefit more with his DW ability, Intimidate. I would suggest this moveset
Like suggested before, use an Expert Belt. And I do not understand why you would use a Physical move on a SPECIAL attacker. Save 252 and drop the attack EV's for Speed, and Earthquake for Hidden Power Ground.
Ugh... Slash, really? Man, Golurk would completely wall this set! Dont put a Physical move on Special attacker. I understand that you are trying to make this guy mixed, but no. 75 Base attack is mediocre; not to mentionit scores no coverage. Rock/Ground type would walk all over your set, so use this.
Now before you look at Thunder's low Accuracy, note that Galvantula's Ability, Compoundeyes, raises it. You said that you wanted to "Slow Down [the Foe]"? Paralysis (Thunder Wave) 1/2 Speed. Energy Ball murders cocky Rock type. And dont worry about Fire Type, Qwilfish has it down, given he doesnt die.
Skarmory is fine.
1/2 of this team has a weakness to Fire type. Dont worry though, Qwilfish is somewhat of a counter, and Snorlax's Thick Fat allows it to resist Fire type moves (Special)
Hope I helped