Recitation of Fatihah

Reciting Al-Fatihah Behind the Imam in Loud Prayers

Assalaamualaikum wa rahmatullahi wa baraktuhu, Bismillah , I have various questions.I would be glad if you help me.I am confused about prayer in congregation.I have read in many books that we have to recite surah fatiha in every namaz.I have a doubt that whether we should recite surah fatiha in the prayer which is recited aloud that is the fajr,maghrib and isha prayer.I read in a fatwa on islamonline.net with id - 1119503544082 that we have to remain silent when imam recites surah fatiha and recite surah fatiha during silent prayers but when i asked in a fatwa about this question on this site , fatwa reference no - 5SH1Bq, the sheikh said that during prayers when imam recites loudly, one has to recite surah fatiha after him.What does after him means?After everyone says ameen should we then recite surah fatiha?please help me on this issue.My other question was about zakat.do one have to give zakat on what he earns or what he save?I earn weekly, so should i give zakat on what i earn?.My last question is about alcohol.I work in a supermarket where i have to put groceries and other items in bags and give to the customers.Some customers(americans) buy alcohol.so i have to put alcohol bottles in the bag. Is that prohibited to put the bottle in the bag and give to the non-muslims? -- My other question is about wudu-Prophet Muhammed(P.B.U.H) said that breaking wind nullifies wudu,but he(P.B.U.H) didn't say the solution of what to do if anyone have problem of breaking wind.He(P.B.U.H) said that every innovation is misguidance.How do we deal with any matter which was not during prophet's(P.B.U.H) but it is now ? Does it considered innovation ? How many times should a person's wudu break in order to be put into category of disabled ? If a person's (who doesn't have any problem of breaking wind) wudu break while he is performing wudu,does he have to start again or he could continue doing the wudu ?The fatwa says that if a person has a problem with breaking wind, he have to make wudu once, and then he could pray,does it apply touching quran also?  If two ulema's have different opinions , whom to believe ? If an imam leading prayers at wrong time , is it permissible to pray alone at correct time ? I am concerned about this hadith - In one Hadith, two reasons have been cited for the punishment in the grave:a) Not exercising precaution from the splashes of urine drops,b) Gossiping.Here in United States there is no water available for cleaning ourselves but i use toilet paper and make sure that no urine is left but after like 5 t0 10 minutes , when i try sitting , some drops come out , i try my best to prevent myself but still can't do . Is my  interpretation of hadith correct which is - A person in punished who is careless about preventing one from urine but a person who is not careless, tries his best to prevent himself , but sometimes cannot prevent himself is not punished.What if go home and wash myself ? Does i considered as a person who doesn't prevent oneself? If a person is memorizing quran and he comes to an ayah where there is prostration,then does he have to prostate everytime he repeats that ayah in order to memorize ? There are thousands of hadiths , what if a person doesn't know some and he is practicing wrong ? Can a person touch quran which is covered by a cloth,without wudu? In a hadith i have read that if one hungry or if the food is ready,he has to eat first even if the salaat has started , is it permissible to miss the prayer or a part of the prayer for eating food if one is hungry? When is it necessary to perform sajda suhu ? Is it performed when a person recites some thing wrong or forgets something to recite ? do we have to do sajda suhu if we pronunce the word wrong like in surah fatiha instead of waladhaaalen , we pronunce waladaleen ? What is the best way to learn quranic arabic , I want to memorize quran and also learn arabic so that when i recite in prayer i could reflect upon myself and have focus on prayer . What is the reward of memorizing quran according to hadith ? Is knowing the meaning of quran fardh so that we could practice on it ?Please answer these questions as soon as possible , Jazakallah.