What is the ruling on someone who perform their prayer after finishing it because they believe they missed a Rak'a, a prostration, or that they did not perform it correctly (thinking their prayer was invalid)?
If he was sure that his prayer is void then reperforming it is an obligation along with figuring out the reason of invalidity so long as this wasn't out of uncertainty. And Allah Knows Best.
Is it permissible for a man to marry up to four wives (polygamy in Islam) for pleasure although he can`t afford that?
It is desirable for the man to have one wife if there was no need for him to have more, if he can't afford marriage forthcoming expenses.
Is Hyena's Meat Permissible or Impermissible?
All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
There is disagreement amongst the jurists as regards the ruling on eating hyena`s meat. Shafi`i and Hanabli jurists are of the view that eating hyena`s meat is permissible. The proof is the Hadith related by Al-Baihaqhi on the authority of Ibn Abi Ammar who said: "I asked Jabir bin Abdulla about hyenas, and he told me to eat them. I said: "Is it not game? He said: 'Yes' I said: 'Did you hear that from the Messenger of Allah?" He said: "Yes." And Allah The Almighty Knows Best.
Is it permissible for a Muslim to escort his deceased disbelieving relative to his final resting place?
It is permissible provided that he doesn`t walk behind non-Islamic symbols, rather he should walk in front of them.