Summarized Fatawaa
• Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
• Should a prayer performer who forgets to offer the middle Tashahod(saying ash-hadu anala ilaha ila-alah) offer Sujood As-Sahw(prostration of forgetfulness)?
He/she should offer two prostrations of forgetfulness at the end of the prayer.
• Should I pick up the newspapers thrown at the street because they definitely contain sacred names?
Praise be to Allah the Lord of the Worlds.
The Messenger of Allah (PBUH) says, "Be mindful of Allah and He will protect you." Part of this is protecting whatever contains the name of Allah. Therefore, if you see a paper containing Allah's name thrown in the street, then you should grab it and similar papers, then burn them in a clean place. Doing so is permissible because Othman (May Allah be pleased with him) has burnt copies of the Quran which didn`t match the main Mus-haf. However, you aren`t required to collect every paper in the street. And Allah the Almighty knows best.
• When does the time of Isha prayer end?
It ends at the emergence of true Fajr(fajr ul sadiq ), and when the second Athaan of Fajr starts.