To answer the first question:
ALL religions in the world, whether or not a deity is involved, are based on the concept that man needs improving/fixing. Something is not complete or not right about man. This definitely marks us as different from the animals!
EVERY religion but one puts the burden on man to correct himself -- with proper learning, proper rituals, proper acts, whatever. However the Judeo/Christian religion is different -- God took the burden upon Himself and when a person gives up to Messiah/Christ, then that person is changed internally and the Holy Spirit takes the responsibility of maturing that person and making him or her complete.
Ancient Jews looked on the Promise from God, and we recognize that Promise was Christ Jesus. There are Jews and Christians who do not put their faith in Christ, despite any words they may use, and still depend on works for self-salvation. In that senst they belong to the rest of the world's religions.
Therefore, for the purposes of this argument, those who fully trust Christ are completely at odds with everyone else. For either all the other religions are right in that man must somehow save himself or biblical Christianity is right in that Christ, who is God, did the work of saving us and will transform us.
If Christ is wrong, then ANY of the other religions will do just fine. If Christ is right, then only Christianity is right and all the others are wrong.
There is no need to 'test' the different deities or religions. The only one that needs to be tested is Christianity/fulfilled Judaism. If that is wrong, it really doesn't matter which other one you choose. You have the burden of somehow saving yourself.
Now, as to the tsunami -- was that God's judgment? I disagree with Aineo here and will say yes. Indonesia is the greatest Islam nation in the world with active persecution of Christians and hunting down of Christian missionaries by some Muslims. Right now word is coming through from missionaries over there that there is a giant swing in many areas to Christianity. They have seen their destruction and our compassion in the midst of it. They will know we are Christians by our love -- and they are responding.
There is no such thing as an accident, in nature or anywhere else.