Missing salaah due to being very tired

Q: I read a hadith that, the Prophet (sallallahu alaihi wasallam) said: “Whoever misses the Asr prayer, then it is as if he has been robbed of his family and his wealth.” (Al-Bukhari 552).

And... In another narration by Al-Bukhari and others: “Whoever abandons the ‘Asr prayer, his deeds of worship become void.”

I am 23 years old and a practicing Muslim since I was a kid. Recently I missed my Asr Salah. I didn't sleep all day/night, So I was very tired. During the afternoon time slept and missed Asr salah though I was aware that it was Asr time. I kept delaying the time and eventually missed it. Now I am scared if all of my deeds have been void. I prayed the Qada' Salah.

But there is also a hadith that says, Anas reported that the Prophet (sallallahu alaihi wasallam) said, "Whoever forgets a prayer should pray it when he remembers it, and there is no expiation (kaffarah) for it save that." Related by al-Bukhari and Muslim.

And... The Prophet (sallallahu alaihi wasallam) said: “The Pen has been lifted from three: from the sleeper until he awakens, from the child until he reaches puberty and from the insane person until he comes to his senses -- or until he comes round.” Narrated by Abu Dawood (4403), al-Nasaa’i (3432) and Ibn Maajah (2041). Classed as saheeh by Shaykh al-Albaani in Saheeh Abi Dawood.

So, is all my deeds/prayers/amals has been invalid or not? I am confused.

Questioning matters of Deen

Q: Im a new convert to islam alhamdulilah and have been for around 7 months now. Im so happy and everyday I try and read Hadith and Quranic verses to increase my knowledge. Having said that I came across a few Hadith which has started making me a little doubtful so I really would love if you can help eliminate those doubts. I was reading a Hadith on Umar bin-Al khattab who suggested women covering up then aya was revealed after peeping on wives of prophet when they went to relieve themselves at night. When Sauda told the prophet, she was embarassed and thus the Aya regarding modesty and Hijab was revealed. I also read a similar hadith which stated that slave women dont have to wear the Hijab. It was to rather differentiate between Free women and slave women? How can this be if this is a duty on all muslim women?

On another occasion, When Hafsa found prophet in her bed with Maria the copt an aya was revealed regarding making matters that are halal haram.

So my questions are: How is it fair that slaves are treated differently with regards to Hijab wearing (its not compulsory). Why were verses from Allah revealed after Umar bin Al Khattab suggested? How is having intercourse with a slave permissible (i.e Mariya the copt) without marriage? Some critics would argue that this is to allow the Prophet (sallallahu alaihi wasallam) to do what he wants. A similar thing the fact that he had 11 wives when the maximum is 4. I dont not hold those beliefs of course, i believe it is slanderous and blasphemous to our beloved Prophet (sallallahu alaihi wasallam) but how do I refute such claims.

Laughing at someone

Q:

1. If someone is short or black, will laughing at them be kufr because Allah made them like that? It will be as if a person is indirectly laughing at Allah's decision.

2. I heard in a hadith that Moosa (alaihis salaam) was dark in complexion (black or something). Will it mean that making fun of someone who's black because he is black like indirectly laughing at Moosa (alaihis salaam) too.