Qasr: How, when and how far one should be before it can be enacted…
The Makruh times (Rising sun, setting sun and after the Asr time has passed)…When are they and how long do they last? Can we pray our Asr QaDa’a right before Maghrib?
When praying four Rakah Sunnah, does one recite an Ayah in every Rakah or do it like the FarD…(Two filled, two silent)…
That’s all and 
s in advance…
Re: Some questions:
1) Really depends for instance a person drives to his/her work 20 miles 5 days a week and for him to really pray as Qasr would not make sence because its not something he/she does once or twice a week/month/year.
2) I am not sure about how long the sun setting and rising last but one can pray their Asr QaDa'a after Magrib.
3) Only when praying FarD and that too if you are praying 4 FarD than the first 2 should be filled and the last two silent as compared to Sunnah where all are filled.
As far as I know...
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P.S.
3) When praying four Rakah Sunnah, does one recite an Ayah in every Rakah or do it like the FarD...(Two filled, two silent)...**
When you say (Tow filled, two silent)...
I assume you mean the first two with Surah Fatiha first than any Ayah and the 2nd two with only Surah Fatiha right?