Verse 6 might be an expression of pride, but what if it is just a rephrasing of verse 1 from a personal perspective… maybe he’s not talking about personal fulfillment, but just actually understanding that because he has been lifted up by the LORD, he cannot be moved.
Within this context, verse 9 does not read as manipulative, but as again a correct understanding of what it means to be human: to praise God and declare His truth. Death seems to be equated with the silence of praise – an end to what it means to be truly human.
The psalm is personal because it does not deny the experience of being estranged from God, but it offers an eternal perspective that invades the personal. The anger/weeping/mourning/distance is temporary, but the singing/remembrance/praise/life/health/dancing/gladness is forever.
But this isn’t just a philosophy – it’s entirely real. The enemies/blood/grave are real. Death is real. This means that God’s rescue is real. He has turned the mourning into dancing. He has clothed us. He’s done this in real time so that we can be the people we’re supposed to be and praise him forever.