My first competitive team

[Rabbitknight]

So I've done a bit of research already, figured out the pokemon and moves I think I'd like to use, using teamamagma's team builder, some poking around nugget bridge and youtube for some builds and have a vague strategy. There's a few things I'm not sure on, primarily items on some pokemon, and Nature/Ev's for most.

Here's my (very rough) team

Lopunny @ Lopunite
Limber/Scrappy
Nature: Probably Jolly
EVs 252Atk/4Def/252Spe
Drain Punch - I'd like to be slightly more survivable than Hi Jump Kick, and the accuraccy appeals to me
Ice Punch
Fake Out
Facade -instead of Return because most people will be trying to burn Lopunny anyway.

Garchomp @ Yache Berry? Life Orb? Choice Band?
Rough Skin
Nature: Probably Jolly
EVs 252 Atk/4SpD/252Spe
Rock Slide
Earthquake
Dragon Claw
Protect/ Iron Head if CB

Togekiss @ Sitrus Berry
Serene Grace
Nature: not sure
EVs not sure
Follow Me
Roost
Air Slash
Heat Wave -I needed someone to carry Fire and it seems like this or Flamethrower

Amoongus @ Rocky Helmet? Black Sludge?
Effect Spore
Nature: Def or SpD?
EVs not sure
Rage Powder
Spore
Protect
Giga Drain

Scizor @ no idea
Technician
Nature: Adamant? one for Def/SpD?
EVs not sure
Bullet Punch
Bug Bite
Knock Off -Needed to find some place for this even if it doesn't get Technician
Protect

Rotom Wash @ Assault Vest
Levitate
EVs Hp/Def/SpA just not sure how much
Thunderbolt
Hydro Pump
Hidden Power Ice
Shadow Ball

So the basic idea here is to bring Lopunny and Garchomp, along with whichever of Amoongus and Togekiss fits the opposing team better to enable Lopunny and Garchomp to remove threats, then whichever of Rotom and Scizor for cleanup. Very Basic, but I'm not sure where I need my EV's and Natures for most of the team because I'm not super familliar with what threats are out there.