5 Box Play Help and Level Set Expectations Support

[MiRai]

I decided with 5 iLvl 380 toons and some abilities setup I would go check out Shadowfang Keep (I think heroic) where I promptly go my arse beat and died quit a few times (with lots of healer mana lol).

1. Should I have been able to easily do Shadowfang Keep with a group of new boosted 120 on Heroic?

You took a newly boosted team of 120s to a level 85 Heroic dungeon in Silverpine Forest, and you couldn't complete it? I just want to clarify this bit here, since it's likely going to dictate what advice people could to give you.