well actually there is not specific or clear different between عندما ,حين and حينما. they all mean when (talking about specific time in which action was happened) We called this in Arabic (ظرف زمان) (adverb of time). This is a short summery of your question.

Yes

Time of the day in Arabic is نهار which means day light and ليل which means night We called the whole day يوم means 24 hours, so ذَهبتُ إلى المدرسة نهارًا means i went to the school in the day light. رجعتُ إلى البت ليلاً means i came home in the night or in the evening.

You can listen to the greats four (Abdelwahab- Wadi3 El safy- Om klthoom- Fayrouz) محمد عبدالوهاب https://en.wikipedia.org/wiki/Mohammed_Abdel_Wahab وديع الصافي https://en.wikipedia.org/wiki/Wadih_El_Safi أم كلثوم https://en.wikipedia.org/wiki/Umm_Kulthum فيروز https://en.wikipedia.org/wiki/Fairuz You can search for their songs on Youtube and soundcloud

Prepositions in Arabic called in a lot of old Arabic grammar books (Prepositions of meaning), so you can know the meaning of them and you will be able to use them according to the meaning: على on في in إلى to عن about فوق above and so on

The third one بيتي وكتابي

هل تعلم اللغة العربية صعب؟

أولاً أظن أن تريدين أن تقولي أوضحتُ أنَّ حروبَ المياهِ ومحاولةَ السيطرةِ على هذا صحيح كلمة (محاولة) معطوفة على كلمة حروب بحرف العطف الواو