i understand what your saying, but look how kishi turn obito into? he was a nice kid kind, and helping now hes just a killer. and kakashi couldent refused the mission beccause he would be punished for that, but look at the chapter where kakashi is surprised that obito is still alive, and how he tells obito aren't you gunna blame me? obito says no beccause its the world that we live in, to further plot this, is that the reason minato had kakashi do it was beccause kakashi was the only one who could catch her off guard thats why.
Have a open mind, why do you think obito tryed to destroy the leaf village? and try to kill his former sensei and his newborn son? its revenge for what he did, minato is a good guy i believe that to but people still dont understand that the kages of each village have to make sacrifices to keep there villages saftey alive, for a perfect example, garra Dad he put a monster into his own son when he was born just like minato did with naruto, there motives were both the same to protect there villages, that is another reason why people must understand is that kakashi didnt murder rin he didnt kill her out of anger or hate, its beccause he was orderd to kill her for what she did which will be explain, its his duty