Man, you posed some good theological questions. Let me try to address them as best I can, but I know I will fail to explain it to you in a way that is sufficient since the internet often is a difficult medium to convey thoughts.
1. Is life masochistic?
let me start by saying that life is hard, but harder for some, yet easier for others. A lot of that is genetic, but some is environmental. I won't go far into the nature/nurture argument, but let me say that life can be good for anyone, whether they are a believer or not. In the days of the early church, it was certainly difficult, due to persecution. The apostle Paul wrote about the sufferings and said they were like a momentary light affliction compared to the joys of eternal life with God. So, a person with faith lives a life in a way that seeks the spiritual nature, and not the carnal. In doing so, a lot of the difficulties in life will not arise (environmental causes lessened) and when there are difficulties, they get through them easier because they are focused on the life to come. This does not mean that there will not still be some environmental issues, because a life before coming to Christ may have set in motion physical ailments that cannot be reversed. What I am saying is that the new life should be such that they will not be compounded.
2. Is the bar God is asking us to reach too high?
I will start by saying the bar was set high under the Old Law, and Jesus raised the bar when He gave the Sermon on the Mount. However, that is the bar that was set in order to earn salvation. Nobody can earn it, because it is the free gift of God, offered by sending His Son to take our penalty of sin (death) upon Himself so the wrath of Gd would be satisfied. I know that concept is difficult to understand, but it was done because of His love for us.
Now, the bar is to believe that Jesus came to die in our place, that He was buried, and that He rose on the third day, which is our assurance of a future resurrection, either to life or to death. The ones who accept this free gift will rise to be with Him, and those who want no part of it will not take part in eternal life. Explaining their eternal punishment is hard to do, because the Bible uses terminology that we can grasp in human terms, but it might be incomprehensible to our fleshly minds.
3. Is God good when He asks us to live a certain way?
In answering the previous question, I hope I have explained that He is good, because He knew we could not do it, so He sent Jesus to do it, and to pay our penalty. That love is why we should live for Him now. Further, we live a certain way, not to earn anything, but as an expression of gratitude for what He has done for us, and for what He has promised us.