Maybe evil is necessary in order to have some good? As without suffering, we would not be able to experience the gretest kind of pleasure.
Perhaps, but this is because God made the universe in a way where suffering is a prerequisite for pleasure. If he was truly ALL good, he would not have made the universe where suffering is a component at all.
You could try and become balanced and comfortable with just about everything to an extent. But in order to be wholly comfortable with anything, you have to be flawless when dealing with such a thing. Can you imagine any person being wholly flawless with any activity 100% of the time? This is what he needs in order to be perfect in one single respect, as otherwise the upsets will cause him to incur negative energy.
I don't even think we can be perfect in one walk of life, the one that comes to us most naturally and easily. Even less so in all walks of life.