The Magmar set you chose seems to be lacking as a support mon. Not only that but not running Protect may be an issue. I wouldn't recommend running Overheat either to be honest. It does do a lot of damage but the special attack drop really hinders you seeing as how Magmar only has Overheat as an offensive option. Heat Wave, Fire Blast or Flamethrower would be more optimal in my opinion
Other than to hit Heatran, I really don't see how HP Ground is useful on this set to be honest. The EV spread for the speed creep on Salamence and this moveset kinda contradict. If you outspeed Mence, why not teach Manectric HP Ice to OHKO it? Furthermore, Ice coverage deals with more threats than HP Ground does. Snarl is debatable because of the higher usage of Milotic meaning Snarl may more than likely backfire. I'd go for Light Screen here if you really need that SpDef increase or Substitute to avoid Sucker Punch and take a hit that may faint you.
Rain Dance on Conkeldurr is a really weird idea to be honest. I see where you are in a way mimicking the Sunny Day Amoonguss used at worlds (though I may be wrong about this) but Rain Dance doesn't have that much of a significant impact/contribution to your team synergy. Ice Punch or Knock Off would be more optimal.
For a Toxic set, Maranga/Kee Berry would be better as you get to increase your bulk then spam Recover to stall out the opponent. Speed control isn't that much of a concern for this team so Ice Beam may be a better choice here to get stronger type coverage
There's really no reason to go dual mega here. Normal Scizor's bulk is sustainable enough to accomplish what you need to here. Just opt for a LO/Lum set.
The idea behind this team is there but this team is still a work in progress. Some of the moveset and item choices hinder the synergy of the team. It even appears as if some mons don't fit in here by my perspective but this is your team so I wouldn't wish to be disrespectful and tell you to change anything about it