That is fine, but remember this life is a test, you could never be a Muslim however it is the truth.
Listen to me brother, you can reject it but always remember this the day will come when
Allah will say why did you reject even after given information?
1) He will not be punished if his autism is really bad, however if his level is not as high and he can think and do things as such, then yes he will be tested but probably not as hard as others depending on the situation.
2) Well, that always is not the case. It is a test for you, to see if you are righteous and keep the child in good shape.
3) Nope, in fact the Bible indicates pregnancy is a curse.
4) To be totally honest, i exactly do not have 100% information on that. Only Allah S.W.A.T knows. It could be a test, it could be due to the way different children are tested differently. But the Qur´án, which is Allah´s word, says Allah is never unJust in the least degree.
Everyone will be judged accordingly, and very just not unjust at all.