inIn response to your main question iI have to mention that every prayer has its frame which comes in the books. We are said that we have to watch our salat to be done as the orders. andAnd hope and request Allah to accept that. As you know all of us have problems in our salat, but hopefully believe in grace and mercy fullnessmercifulness of Allah to accept our incomplete salat.
For reading Qaza: ItFor reading Qaza:
It is better to pay attention to this point that the Salatsalat is a right to godGod. It is not optional. when we accept monotheism and prophecy by tongue, we must prove it by Actact. thatThat act is salat and fasting therefore when we have qaza in salat we have to readoffer them whenever we can.