What is outer darkness? It's not the lake of fire. Fire makes lightness not darkness. Is it being tossed into outer space? Where it's cold not hot?
I think all this is symbol-speak, in terms of images commonly understood back then. I don't think it should be taken literal. So much of it was common mythology tossed around long before and in common currency.
Make of it as you wish. To each his, or her, own.
But I'm not much on bogeyman Christianity. I grew up with fire and brimstone sermons, meant to scare people to Jesus, and everybody else.
As a result, I'm numb to hell-fire preachin. Overloaded, actually.
But I know people who awake with panic attacks from fear of damnation. Won't all these scary verses just exasperate those attacks ... not, perchance, bring needed salvation?
Scaring people to Christianity in the end is counter-productive. And why scare believers?
Some people love scary movies. So I guess some Christians like to be scared ... for those I present :
"The bow of God’s wrath is bent, and the arrow made ready on the string; and justice directs the bow to your heart, and strains at the bow: and it is nothing but the mere pleasure of God, and that of an angry God, without any promise or obligation at all, that keeps the arrow one moment from being made drunk with your blood."
~ Sinners in the hands of an angry God - Jonathan Edwards
http://www.ccel.org/ccel/edwards/sermons.sinners.html