I get the impression that this card wasnt really designed to be a commander, and that its instead a legendary for the purpose of other formats
And while that format makes color-heavy decks easy to run, mono-color decks still have a place, and they aren't weak or boring by any measure
You dont really want to draw multiples, but some mode of the card always ends up game-breaking
Generally no, damage is still dealt to blockers
You can tap Hazel and pay two life to tap a bunch of untapped tokens you control, adding mana in any combination equal to the number of tokens you tapped
Then theres the Foretell ability, which lets you cast it in preparation for later turns , where you can easily cast it for only one blue mana