One hit from tsunade would be pretty disastrous, but I don't think it would kill the raikage with a direct hit. It wouldn't hit gaara because of his sand, but it would still be a strong hit. Ohnoki can fly and won't be hit. Mei doesn't have a defense to where she won't be hit, she would likely die. Remember Jaraiya took heavy damage from Tsunade's punch and he is quite durable, so anyone without a super durable body or a defense will likely die in one punch. If a direct punch hits any of them they all die except the raikage.
Completely agree with the range thing. Ability to avoid is also a factor, I think that would be called agility/speed.
Well that depends on how you kick the bones of course. You won't break some bones hitting them in their strongest position. But bones are more fragile in some places and positions than others.