Before I try to answer, I just want to let you know I personally am a Christian, so my answer will be biased.
As to why there is suffering, it's because we chose suffering. I hope you don't mind a story to help me try and prove my point.
God made everything perfect, with no pain, and no evil. But, since he loves us, and wants us to love him back, he gave us a free will. Because for there to be love, true love, there has to be something equally as compelling as love. If you have a girl friend(Or boy friend), and love him/her, you want him/her to love you. If you point a gun at him/her and say "Do you love me?" He/She is probably gonna say yes cause they're afraid of what will happen if they don't. That's forced love. God didn't want us to be forced to love him. God also gave his angels free will, and Lucifer was jealous of God and wanted to have his power, so he resorted to treachery. As a result, God had to make a 'prison' for him and the angels that helped him. That is why he made Hell. See, he didn't make it for us. We choose to go to Hell by the way we act. Sort of like a person who goes and robs a bank. He could have chosen to not rob that bank, and thus avoid prison, but he robbed it anyway. Anyway, I'm getting off track. As we know, God said to Adam and Eve "You can have everything, just don't eat from that tree" Again, God wanted us to choose to love him, so he allowed that tree to be there so that we could choose either him, which was good, or the tree, which was wrong. Satan, of course, hated man because they were made in the image of God, so he took the form of a serpent and I think we all know what happens next. Eve could have chosen to resist, but she didn't, and she ate the apple, thus bringing evil onto humanity.
So, basicly, we were given a free will to decide if we want to do good, or evil. We chose evil, and now we're dealing with the repercussions. As to that story you linked.. (In response to the first chapter about why bad things happen) In Job, God allowed Satan to do anything to Job, but kill him. God doesn't hurt people. He tells Satan that he can hurt them. This (I believe) is done for various reasons. In Job, it was done because Satan said that "If you take away his possesions and blessings, he will curse you" So, God allowed Satan to do that to test Job's faith in him. Wheter or not this is always the case, I'm unsure.
As for the second and third chapter about natures:
Again, God made us with free wills to choose right from wrong. Everything was perfect then, and we knew nothing about evil. God made us pure and perfect, so he isn't responsible for the fact that we chose evil.