Taking an interest bearing loan to save oneself from paying tax

Q: A person deals mostly in cash and does not deposit in the bank in order to avoid showing too much income and paying exorbitant amounts of tax to the government. However, he cannot purchase large items such as properties and cars etc as it has to be done with "legal" money.

The only way out for him will be to take a loan from the bank in order for his purchases to be recognized legally. He will offset the interest payable with the interest he receives from his bank account.

Can this be a valid excuse to enter into an interest bearing loan with the bank?

A Muslim who carried out bad deeds will eventually go to Jannah

Q: I want to ask a question with reference to Surah Muminoon, aayat 103.

Do the people whose bad deeds are heavier on the scales will go to hell fire eternally? It is mentioned in the aayat, but according to a hadith, a Muslim who died with the Aqeeda of tawheed will enter paradise eventually in the end.

Please explain this aayat if a Muslim whose bad deeds are heavier in scale will go to hell fire eternally or temporary?

Using Smart Shopper points

Q:

1. Is loyalty points and the money attained by means of this permissible? Example: Smart Shopper points.

2. Also, if a person works for a company who reimburses him for his travel, will it be permissible to fill up at a garage which gives him points for his petrol.