Drug addict leading taraweeh salaah

Q: I want to know something about drugs. I will be leading taraweeh for the first time this year. Unfortunately, I am in the grasp of drugs. Is it true that if I take them within 40 days of Ramadhaan, the taraweeh I lead will not count?

Also, does this apply to drugs other than marijuana, like molly, cocaine, and lsd?

Please take into account that I am trying to stop, but slowly as the withdrawal effect is immensely strong.

Paying zakaat on one's contribution towards a provident fund

Q: At my previous job, some years back there was a provident fund which I contributed a certain percentage and the company contributed a certain percentage. However after I left that job I forgot about that money and now while trying to take it out from the fund, I am experiencing difficulties as many years passed by and the account became redundant. Do I have to pay zakaat on that amount.

Reciting behind the Imaam

Q: When praying behind the imam in Zuhr and Asr prayer, should we recite Surah Fatiha and a Surah in the first 2 rakaats and only Surah Fatiha in the last rakaat.

In Fajr, Maghrib and Esha, I know we should keep quiet and listen but in the last 2 rakaats when the imam is silent, should we recite Surah Fatiha only?

Wearing one shoe and walking

Q: What is the explanation of this hadith:

Sayyiduna Abu Hurayrah (radiyallahu ‘anhu) reports that Nabi (sallallahu ‘alayhi wa sallam) said, “None of you should walk in one shoe. Remove both or wear both”

(Sahih Bukhari, Hadith: 5856 and Sahih Muslim, Hadith: 2097).