WOW!!! It's amazing how u focused specifically on the exact same things I reacted to as well, all your points except #3. Sure it was a little cliche I will give you that, but not sure what u mean by "fake"- that seems like an odd comment. The reason I don't feel the same w/you on that point (like I do with you on the other points you made,) is that I see the non-earthlings as not as emotionally in-depth and comfortable expressing their selves. That's why Rocket is so apparent and transparent with his emotions. He acts one way but it's clear to see that he feels another--- same goes for Gamora, Nebula, and Yondu. It's almost like they're 12 year olds emotionally. The one emotion the group as a whole seems comfortable expressing is comradery. So keeping in mind what I said, when I see those scenes that would normally come off as corny, with this bunch they are more innocent so it actually comes across to me as heartfelt and sincere and works beautifully getting the audience to buy in to the scenes authenticity--- well at least for me any way.
But bravo to you on those other points cuz i promise you I felt the exact same way!!