First up, I am a Christian, but I'm not replying in order to 'convince' anyone of things they are obviously not willing to believe. I'm also not writing so as to put myself, my beliefs or God in a position to be ridiculed. I am writing because a question was asked, and I might be able to help shed some light on what can be a rather confusing topic. Furthermore, all answers are given from a Christian perspective and on the premise that God is real.
"Why do I have to have an afterlife? I mean my dog and bird get to just die. And don’t say “because your made in his image”- I didn’t consent!!!!!!
"Why is this at all necessary? I wasn't given a choice to be born- had I been, perhaps I might have declined given eternity is a while..."
"If the non-believer is content with no afterlife- why can't god grant them (in his all-loving character) the wish of just...dieing? It's dead simple."
Human beings are made up of three components - body, soul, spirit. Dogs and birds aren't. Body is obvious; hunger, thirst, physical pain. All the chemical, touchable, measureable stuff. The soul is both immaterial and material (from the soul comes the need to be loved, as well as our emotions) and in it's most basic sense the word 'soul' means 'life'. Human beings in essence are souls and our souls are naturally tainted towards evilness as a result. The soul leaves the body upon physical death. Unlike 'being a soul', humans have a spirit. Our spirit is the immaterial aspect of humanity that connects us to God. That's where the terms being 'spiritually dead' or 'spiritually alive' come from. Spiritually alive meaining when an individual believes in and has relationship with God and are so choosing to 'connect' with Him.
To answer your question of "Why do I have to have an afterlife?", try to shift your perspective on the issue even if it is just for a moment, to try to understand the Christian view on this - I'm not necessarily asking you to agree, just try to be open to the idea... There are going to be a few concepts the entertwine, so I'll present them individually first, then relate them to each other.
1)God exists outside of time. As humans, we cannot operate or even truly comprehend what it would be like if time suddenly became obsolete. That's why eternity seems so incomprehensible.
2)God loves you. Whether you like it or not, whether you acknowledge it or not, whether you choose to believe it or not, GOD LOVES YOU. It's a perfect love, a love that never fails, a love that will never let you down, a love that will never hurt you. It's not an abusive love, nor a manipulative love. It's a love that would lay down his life, for you.
3)God desires relationship with you more than anything.
Because God loves you so much and desires relationship with you, He wants to spend eternity with you. Because He knows how much love He has to pour out on you and to bless you and to make you whole, He knows that Heaven is well...heaven. (There is a song that captures the essence of heaven really nicely called You Hold Me Now by Hillsong if you want to look it up.) Why would a loving God want to let you just die and have nothing, and let you miss out on the joy and perfection of Heaven? That would be rather contradictory of Him, I think. However, like you kind of seemed to vaguely understand, you do have a choice. You can accept God and believe in his awesomeness, ultimately allowing Him to bring you into eternal life in Heaven, or if you don't want to accept that, like Satan (don't get me wrong, I'm not saying you're the devil) you too can choose to spend an eternity without God. I'll go into that a little later and it will all tie together even more.
So in light of this, whether or not you consent to "having an afterlife" is irrelevant.
"I'd have to say the common Christian response holds the worst logic ever- so the "loving" god not only needs to lock you away from him (because you "choose it"- something I'd argue, having "faith" is impossible for many atheists!) but you need to also suffer torment."
Let's start with a definition of faith:
faith:
–noun
1. confidence or trust in a person or thing
2. belief that is not based on proof
Looking at the definition of faith, all atheists in fact have faith as they hold a belief, trust, confidence etc etc that there is no God. Agnostics in essence are the only ones who don't have faith because they are unsure of their beliefs about God and God-related issues, but that's irrelevant here.
In response to the perceived Christian response that "holds the worst logic ever" (which in fact the argument "the "loving" god not only needs to lock you away from him but you need to also suffer torment" is actually not at all aligned with the beliefs of Christianity), what seems to be missing from any response I've read is Satan's role in relation to hell. I'll try to put it as simply as possible... God did not create hell. Nor does God force people to suffer torment or pain. Satan (the devil, ultimate evil...you get the picture) rejected God for want to be more powerful than God and so through this rebellion became the opposite of everything God is. For example, God is love/life/light/perfect/good/Creator/peace; Satan is hatred/death/darkness/corrupt/evil/Destroyer/torment and so on and so on. So God did not create hell and consequently does not lock those who don't have relationship with him (because ultimately Christianity is NOT about following a religion, but is all about relationship) in hell. Satan created hell through his rejection of God and because God allowed Satan free will, just as he offers us free will, God also allowed Satan supremacy over hell, which in essence is the absence of God and thus the absence of the aforementioned nature of God.
"Do you respect "theologians" as an academic, even if they have done a phD?"
I think this question is obviously going to provoke a vast array of responses. Life I said before, I am a Christian and if a Christian "theologian" presents ideas concerning Christian beliefs I will listen to what they have to say. Whether or not I agree with their ideas will be influenced by their use of Biblical support that is in context (Scripture used out of context is the primary cause of many misconceived ideas, philosophies and arguments. In fact, it's often seen in the doctrine of cults), as well as how it aligns with the nature of God as understood through the Bible. As far as theologians as academics, I'd say sure, why not? They've studied hard and put in a lot of work into topics and concepts that aren't particularly easy to grasp. To be honest though, I don't think whether theologians are classified as academics or not isn't greatly important in relation to your other questions.
"I mean is there really any difference between them and someone doing their phD on Harry Potter?"
I suppose the difference is that 'religion' affects the world to such an incredible degree that an understanding of what it is all about is inmeasurably important, whether you agree with the theologians or not. That goes for any religion really, not just the Christian faith. Also, theologians deal with a greater scope of concepts like ideas concerned with Creation, what existed before creation, why we're on earth, what happens after we die, why is there bad things in the world etc etc etc. All that deep stuff. Somehow I don't think it's quite the same as Harry Potter.
"These people are experts on what exactly? How to interpret Bible passages? The inner workings of "gods" mind?" "
There's no real question here unless you want to rephrase it. All you need to do is look up a dictionary definition of a theologian/theology.
Look, at the end of the day whether or not you are open to the whole concept of a God who loves you is up to you and will influence how you respond to the commentaries and ideas that not only I've presented here, but that you will encounter throughout your life. I hope that this essay of an answer helped throw some light on your questions from a Christian perspective.
Just remember, Christianity is not at all all about laws and rules and regulations. It's about relationship and it's about love.