The first two points of Mark 9 are ones I already answered in Matthew 16 and 17, but I'm going to address them again here since they oddly go together and splitting them into two chapters I think misses the real subtlety of the matter. Yes, Jesus made a prophecy that sounds like he's saying that people there with him would be alive until the end of the world. But what if that's not what he's really saying? Look at the SAB's page for the very next issue, "When was the transfiguration?"and read those quoted passages. My point? The Gospel writers understood that there was something intrinsically connected between what Jesus was saying about "see[ing] the kingdom of God come with power" and the following transfiguration. I put it to the reader that it was this transfiguration itself that Jesus was referring to, and three men (namely Peter, James and John) lived to see it because it was only about a week away.
I answered the question of whether John the Baptist was Elijah in Matthew 11. I'm not sure exactly what the SAB finds so upsetting about Jesus' words in verse 19, so no comment.
The SAB asks "Who makes people deaf and blind?" which I answered back in Exodus 4. The questions about casting out devils I answered in Matthew 7. The question of who is for or against Jesus I answered in Matthew 12. The question about whether Hell exists I answered in Matthew 10.