[In response to "There's also the issue of indoctrination - if your religion is true, is it fair for God to punish those that were taught as children that a different religion is the true religion?"]

For the last one, I would say yes because that is justice. If the law is true, then the law has the right to punish whoever misinterpreted it or just straight up ignored it. Also, they had plenty of time to find about Christianity, which is by the way, not a religion but a relationship, and are smart enough to research about it. If they did not, then it's not God's fault, its theirs and they must pay the consequences for their actions. One should not blame something like this on God but rather on themselves because there is no reason not to find about Christianity.