1.
In Christianity, how is YHWH's omniscience reconciled with free will?
In other words, how can God know the future, yet still allow us free will? If God knows what will happen, then he knows what we will choose to do. If this is true, then what you will decide in any given situation has already been pre-destined long before you even existed (and thus free will does not exist).
I believe that God's omniscience only goes as far as he allows it to. This is evident in how God throughout the Bible seems to show emotion, or even regret (Noah and the flood) at the decisions he makes and the ones that man make. In other words, I don't believe God knows everything that it is logically possible to know, just as he cannot cook a burrito so hot that he himself cannot eat it. God can does not contradict himself, therefore we have free will.
2.
Also, what is the purpose of prayer? When a person's prayer is not answered, or something horrible happens, one often hears how YHWH works in mysterious ways, and that he has a "plan" for everyone. If this is true, and he does have a huge "master plan" for every person, why bother praying? Should he re-adjust and rewrite his entire plan merely because you need help? There's no point in trying to draw his attention to a problem either, as he is all-seeing and all-knowing. It seems to me that prayer is mostly for the peace of mind of the prayer, rather than having any sort of actual effect on the outside world.
I don't believe that God causes disasters to happen. The idea that disasters are somehow part of a larger "plan" are alien to the Bible. That being said, God quite often uses disastrous situations for the better (Romans 8:28), as is evidenced by the vitality of the church in parts of the world where Christians are persecuted the most. This kind of goes along with my answer to question one, so within these parameters I believe that prayer
does influence the course of events.
3.
What happens to those who die without having had a chance to accept Christ? Supposedly you go to the flaming demon zoo if you die without being saved. Is it really fair, though, to send someone to eternal torture and punishment for not repenting of sins they didn't know were sins? All humans sin during their lives, and depending on who you talk too they might bear the burden of Original Sin from birth (which is a gigantic load of horseshit unto itself, but I digress). If some people are not even given a chance to be free of their sin: if they never even hear of Jesus or YHWH during their life, then they are essentially trapped. I cannot see a supposed "Good and Merciful" god creating such a trap.
There are different schools of thought on this, and I will discuss two of them.
The first holds that in the absence of a presented law, it is impossible for people to be judged in its accordance. Therefore people who do not hear about the Gospel cannot be judged according to it.
The other opinion says that because man is sinful by his nature, not hearing the Gospel does not justify one in the eyes of God. My beliefs lean strongly towards this view (though not completely) and I will explain why:
According to the Bible, the world was at one point void of sin, but by disobeying and separating themselves from God (Adam and Eve), sin entered into the world and has been present in the entire course of human history. Because God is good, and there is need for divine justice in accordance with God's nature, he set apart the descendants of Abraham as a people group that would testify to his greatness and create a spiritual kingdom on Earth (Isaiah 49:6). The Mosaic Law and customs of the Old Testament satisfied God's need for justice, but only if they were obeyed. The failure of what we now call the "Old Covenant" led God to take a new direction. By taking on the form of a man living a blameless life, and being killed as a "criminal", God, in the form of Jesus Christ was able to redeem all the evil of every sin committed by every human being in the past, present, and future. Thus back to the original point, man screwed himself and the generations have payed for it. But Jesus by his own sacrifice has provided a way for reconciliation with the father. As to the perception of hell, a lot of what we believe about it is based off of Medieval teachings, not necessarily biblical ones. I think that there is some strength to the argument that those who never receive the gospel are given a chance to redeem themselves before they are judged. As far as I know, every depiction of people in hell in the Bible relates specifically to those who hear some form of the gospel and choose to reject it (Matthew 22:12-13).