If Chandelure's Hidden Power type isn't Fighting, you can use Substitute over Protect so that it protects Chandelure from status and gives it a defensive buffer against attacks while it sets up Calm Mind. Use Leftovers as the item so that it doesn't get worn down by residual damage from creating Substitutes, as well as battle damage in general.
Poison Jab has terrible coverage on Conkeldurr. Instead, use Payback to help deal with Psychics and Ghosts or Stone Edge for fliers. When B2/W2 come, you can use Ice Punch for Gliscor and Landorus.
ThunderPunch is an inferior option on Electivire compared to Wild Charge (even though the recoil stings a bit). When B2/W2 come, replace it with Ice Punch. Also, since Electivire has excellent coverage, use an Expert Belt. But Electivire isn't as good as it used to be, so you can consider Jolteon over it:
-Hidden Power (Ice/Grass)
-Signal Beam/Shadow Ball
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Choice Specs/Air Balloon (?)
Ability: Volt Absorb
A Quiet nature wastes away Simipour's good Speed. Simipour also doesn't have enough natural raw power to be a sweeper unless it has Nasty Plot; it also doesn't have good defenses. Rotom-W has the power and bulk to be a good Choice user or serve as a bulky attacker:
-Hidden Power (Ice/Fire)
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Specs/Choice Scarf
-Will-o-Wisp/Hidden Power (Fire)
EVs: 112 HP/252 SAtk/144 Spe
What's Porygon-Z's Hidden Power type? If you can't remember, go with BoltBeam. Also, Porygon-Z's average Speed and defenses make it hard for it to sweep. You can also use Trick in conjunction with the Choice Scarf to cripple walls.
Durant really should take advantage of Hone Claws to fix the accuracy issues that Hustle brings. Said move also makes Durant more powerful than it already is:
-Rock Slide/Stone Edge
EVs: 8 HP/252 Atk/248 Spe
Item: Life Orb/Wide Lens/Focus Sash
When B2/W2 come in, you can use Superpower to let Durant hit Steels hard.
Scizor is something else you can consider over Durant. It's bulkier and has priority Bullet Punch:
EVs: 248 HP/252 Atk/8 SDef
Item: Choice Band
EVs: 252 Atk/4 SDef/252 Spe
Item: Leftovers/Life Orb/Iron Plate
-Bug Bite/Brick Break
EVs: 252 HP/40 Atk/216 SDef
Item: Leftovers/Iron Plate