the death penalty is inhumane if your charging it for just a murder, and no, it wouldnt help.
a death penalty is just as bad as the murderer
No, for all crimes. But for crimes like murder (things which are highly unacceptable in society) the penalty should be so strict that you'd think a 100 time before committing such a offence! In such cases, yes death SHOULD be the penalty.
For the safety of other people in the society!
Might be, but if its imposed then murder rate would dramatically fall, wouldn't it? Benefit of one or the whole society is more important?