I agree with most of your points. None of the cringe humour hit the mark for me, and neither did Groot. It felt like it was cute for the sake of being cute (and selling stuff). I did, however, like him on the Captain's ship. Drax is great, Mantis is great, most of their interactions together were not. The arrow and ship scene is still one I love, there's something about it that's just so, so satisfying. Glad you enjoyed it more the second time around.
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https://m.youtube.com/watch?v=x9gN2hdybFY