Sajda-e-Sahw

Q: If you read attahiyaat twice in one rakaat do you have to do sajda sahw and if you read surah fatiha twice in one rakat do you have to do sajda sahw?

Q: During Quran recitation or during the Zikrs and duaas while in salaah if one stops at the half of a word and after 2 seconds one continue does the Salaah break? For example when one wants to read "Alhamdulillahi rabbil alamin..." one says "Al..." after 2 seconds "...Hamdulillahi..." or one starts from begining again. Another example when reciting "Ihdinas siraat al mustakim..." one says "siraat al..." then one does restart from "Ihdinas..." Or when reading "...musteqim.." one stops after after "muste..."  then one re-reads it. Does such things break salaah? Also if one makes such an error that would break the salaah, if one re-reads the relevant place correctly again, does the salaah become valid again?

Q: Is the sajdah sahw only waajib in those instances when it is allowed to pray? For example if one is praying Fajr and after the salaam the sun does rise, does he need to do sajdah sahw or his he absolved ? If not does he later need to repeat the Fajr (because he did not do sajdah sahw)?

If one praying Asr and after he makes salaam the redness of the horizon is visible, does he need to do sajdah sahw or is he absolved ? If not does he later need to repeat the Asr ?

Q: If I forgot to add a surah after surah Fatihah in the Fard prayer that has 4 rakaat, do I make this up by reading surah after surah fatihah in the 3rd rakaat or 4th rakaat? Do we have a choice of choosing 3rd or 4th rakaat? Of course, we still have to do sajdah sahw.

Q: Should you make sajda sahw if you read surah 110 in the first rakat and any earlier surahs in subsequent rakats?

Q: A person forgets to make sajdah sahw, is it wajib for him to repeat the salaah?

Q: A salaah in which a wajib was left out, it is wajib to repeats within its time. But what if the time is over, is it still wajib to repeat it. Also such prayer can it be prayed at any time like after few days or is the order to pray it befor the next prayer obligatory? Do all makruh tahrimi acts, like omitting wajib, prayed with pictures on the cloth or towards a picture make it wajib to repeat the salaah? Or is it in some cases only sunnah or mustahab to repeat it?

Q: If one is performing Asr 15 minutes before Magrib and a mistake in salaah is made which neccasiated sajdah sahw, should he make the sajdah sahw or omit it? If he has to omit must he re-pray the salaah since does leave out a wajib? 

Q: If a person recites a Surah after Surah faatiha in the last two rakaats of a four rakaat fardh Salaah, will sajdah-e-sahw become waajib?