Or just accept the simple answer to all of it: There is no god, and we live on a cooling earth, where plates move, snag, and let go with tremendous violence. Volcanoes come from the molten center pushing on the breakable crust. Air masses move and interact with large consequences of wind and water.
Sorry,
There is a God or we would not have an earth at all. Read Genesis 1 and 2 and believe.
Why is there something rather than nothing? Some physicists have tried to answer that question (Lawrence Krauss, Hawking, etc.) but their efforts have been universally panned.
There are a number of good proofs for the existence of God, none of which to my mind have been successfully refuted. Atheists claim their counterarguments are bulletproof, but they are flawed either by attacking a weak version of the actual proof or by equivocating on terms they don't fully understand such as 'necessity'.
So from my limited point of view we are living in a world created by some very powerful (or maybe infinitely powerful) being that appears to have more senseless suffering than necessary.
Ethical philosophers are busy addressing lots of detailed ethical questions about what we should do in specific instances or how we should live our lives. They disagree among themselves, but at least they are engaging the questions "at the ground level".
If someone knows of a theologian or Christian philosopher who is engaging with specific forms of seemingly senseless suffering and working to show where the meaning is, or how this suffering works for good in the plans of an all-powerful and hopefully all-loving God, then I would be interested in reading that.