The moral influence theory - basically Jesus showed us how to act. This is fairly liberal but we actually do want to "be like Christ."
And the final theory, I don't know. They start to overlap and as you've seen they just kind of switch the enemy a bit each time. I like the Perfect Penitent. As I recall Lewis argument, what is the one thing God can't do? It isn't a trick question. God can't repent. But in fact, he did submit himself, for our sins. And through this, enabled us to follow him also in perfect penitence, perfect repentance. But certainly Jesus life was also a sacrifice for my sins.
The next question is how covering was this sacrifice? We can run to the end and ask the same question in a different way -- who goes to hell? This is the subject of McLaren's last book in his trilogy -- the last word and the word after that.
What have we learned? Scripture encourages us to take a view that Jesus death and resurrection accomplished "something" pretty specific, though it doesn't "nail" it down. The theories were usually put in place when someone came up with something that didn't stay true to the story. Scripture hints at the trilogy but doesn't mention it specifically and came out of defense that Jesus was "a" son of god, not "the" Son of God.
It may be ok to call everyone forgiven, but the real question is does every one go to heaven. The answer according to Scripture appears to be unquestionably no. The problem with Scriptural hell is that is described very differently in different parts of the Bible, and that our traditional views are often based on fictional books like Dante.
If you really want to have a conversation about hell, pick up McLaren's last book in the trilogy.
Whether everyone is forgiven or not, it is certainly my job to bring people to reconciliation with God and so I must see them as a person of eternal worth and value and as forgiven in God's eyes. Doesn't God say to the disciples, "If you forgive them, I will forgive them."? It is even more crucial because I don't think their destination is guaranteed and in fact, I think it takes a devoted "Following Jesus" to assure your destination. A simple belief may get you in, but I wouldn't feel assured. I've babbled on a bit past where I should have ended. This may be getting me into trouble lately.