Peter gets a lecture

In preparing Mark 9:14-10:52, I've really got to start at 8:27 and work to 10:52. In fact, I've really got to get an overview of the gospel.
So I've been in what I thought was familiar territory: Mark 8:27-9:1.
Familiar? I've never even looked at the map.
The whole section 8:33-9:1 now reads as a lecture to Peter. Three times Mark uses epitimao, to impress, insist on or rebuke. Jesus insists that the disciples don't speak of His Messiahship (8:30), then Peter insists Jesus is wrong (8:32) and finally Jesus insists to Peter that he is talking Satanic rubbish (8:33). Note how Jesus begins teaching about His sufferings, and that they "must" happen - they are essential to His mission. We can assume He was discoursing at length. Which means Peter decided to discourse at length in 8:32, where he begins.
What I find shocking is how Jesus notices the other disciples, turning from Peter, and rebukes him. Then Jesus calls the crowd and makes an invitation to discipleship, Peter presumably still in the position of rejection behind Him. Peter is rebuked and rejected and Jesus seeks new disciples.
At the heart of the invitation is the question, "how will you ransom your life." Each verse is explanatory of the last in 8:34-38. In simple terms, it goes like this: die and become My disciple (v34) because only dying will save your life (v35) because even the whole world is no gain compared to your own life (v36) because there is nothing you can give as ransom for your own life (v37 - antallagma). So don't be ashamed of Me and My words - because they are about the ransom God will give (10:45). Verse 38 comes over Jesus' shoulder to the shocked Peter as further rebuke, to be compounded, I think, in 9:1. Some will still be alive and see the Kingdom come in power, but that implies some won't be - supremely Jesus, who must die for it to come. Die to your worldly mindset, your worldly ambitions for power and public glory, those Satanic temptations once set before Me (Matt. 4:1-11), says Jesus to Peter. Die and lose everything you value for me and this Gospel of My necessary death as ransom: for how else shall price be found for you (cf Psalm 49:7-8).