Is it moral to deal with something at the end when you have the power to deal with it now and instead choose not to? Especially if by dealing with it now you could alleviate suffering in the future?
I don't think so.
I fail to see the relevance. Are you saying that God's creation of this arena and all things in it and all the harm that follows is justified by a later reward in heaven?
Sounds a little like [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] fighting.
Actually, this is how many parents raise their children. You let them make mistakes to learn lessons.
You got to let your 15 or 16 year old kid go out to their friends house to stay out over night. They might be smart enough to not do heroin but surely one day you very well may get a call from the police that your kid was caught drunk down by the river, or they come home with a black eye or something.
You could have prevented it, theoretically, by always watching over them and interfering... Especially if you were omnipotent and omniscient.
However, what would they have learned?
You learn partly by making mistakes and partly by observing mistakes.
The best way to learn why things like fighting are wrong is to do them. The best way to get a taste of why drug addiction and other addictions are wrong is to spend a few nights in a row binge drinking.
When we see the examples of people getting diseases and dying we can also learn from their mistakes.
God will judge as how He sees fit and we will get whatever judgment that He passes down, whether it is an extended period in purgatory or whatever it is He decides. I really cannot claim to know how things are judged other than what is put out in the Bible and to be honest the Bible is incredibly vague on it.
Here is a question, isn't human morality, if there is no God, based solely on our own concept of observation and learning lessons about right and wrong based on judging the results of what happens by our actions?
In a way we really are fulfilling God's plan even if we are atheists or agnostics because we are using a similar means to make what generally are similar conclusions.
Of course, there are some extremists here who come to very strange conclusions, but generally speaking, the morality of all healthy societies are very similar.