It is prohibited to wear clothes on which there are images of animate beings, but praying while wearing such clothes is valid.

The one who has prayed without purifying himself has to repent and seek forgiveness, and resolve not to do such a thing again. Allah accepts the repentance of those who repent to Him. However, he does not have to enter Islam anew. Additionally, he should repeat the prayer that he offered without purifying himself.

If the Muslim is in a place where he cannot determine the direction of the Qiblah, then he should pray facing the direction which he thinks is most likely to be the direction of the Qiblah, and he does not have to repeat the prayer after that. Rather his prayer is valid but he does not have to do anything else.

If delaying the prayer means that one will miss out on praying in congregation and will pray it alone at the end of its time, then it is prohibited because it means not praying in congregation so long as one does not have an excuse for not praying in congregation.

The regular sunnah prayers that are offered before an obligatory prayer must be done after the time for the obligatory prayer begins.

Praying in cars, planes, trains or other means of conveyance, is not permissible unless there should be the fear that the time for the obligatory prayer will end before reaching your destination and it should not be possible to get off and pray on the ground.