What can I say that you don’t already know? 😜
The part involving the Polish promises to abandon the “historic claims” is (IMO) rather on fantastic side:
who in Poland would have an authority to give such an assurance with any degree of it being believable? Anyway, why would Russia need such an assurance after Napoleon’s defeat?
Why would in 1814 Russia, Prussia and Austria need a buffer state between them? They were allies and the only point of contention related to Poland was a perspective of having vs. not having a reasonably big sized Polish state with any degree of independence.
What would be Alexander’s reward for his anti-Napoleonic efforts?
Resettlement idea? Yes, sure. To have a small area overcrowded with the exiled Polish nobility (I suspect that the peasantry did not give a damn) with no money, no useful skills, no land (with the serfs) and obvious wish of revenge for losing their estates. Would work just beautifully for everybody. 😜