I think these are perfectly natural questions for someone exposed to a formal church, but it's also a narrow view. Please don't cast the thought of God out of your mind. What follows is just my opinion but I hope it helps you...

God is always just. He is not a man in the sky. I think this is why people start to think "well, he's not a nice guy" and turn away from Father-Mother God... because they were taught he's a man in the sky who just arbitrarily decides to do good and bad things to us. NOT the case!

God is not simple. It is important to fully understand "the Lord giveth, and the Lord taketh away." This doesn't mean he's a man in the sky giving us blessings, then taking them and laughing. That's silly.

We are on the material plane, bound by karma of all our past lives, bound by material laws and the karma of the human race. Blinded by illusion. This is not a perfect place- that is the nature of the material world. Our souls chose to come here to learn, and accepted this bargain as we entered the illusion of separation. Have you ever considered that bad things happen for a reason? That perhaps if a bad thing happens to you, it is because of past life karma? Even if we are freeing ourselves from this karma, we still inhabit imperfect material bodies in a material world, at the mercy of material nature. This is the Law, it is how it is here. It doesn't mean God is cruel.

And no, I don't believe that the guidance of Christ is outdated. Here's the sum of it: forgiveness, love, and sacrifice. Still rings true today, if not more so today. But are there outdated teachings in the Bible as a whole? Certainly. Discern for yourself.

Lastly, you talked of sin and inhibition. Go within yourself and seek the answer to what is wrong (for you) and right (for you). Pray, search your heart of hearts.

Avoid "sin" or negative actions because you truly see the error in them and don't want to do them. Avoid them because they clash with your true purpose and life plan. To try to do what is right with God in our hearts is not imprisonment. You may feel imprisoned because you are letting a church tell you "do this, don't do this" and following these rules out of blind fear.

You will feel all the more free when you discern for yourself, in communion with God (however you perceive him/her), what to do. The Law is written in your heart.

P.S: I know what it's like to be "mad at God" and there is no shame in it, in fact in the stories of Krsna, sometimes his devotees were angry with him and this is considered a valid way to interact with God. But I hope you open your eyes and see that God has never once abandoned you, and there's a purpose for everything.