Permissible and Impermissible employment

Q: I have a furniture and appliance store where we sell and fix furniture and appliances. 

Can I fix and sell TV's? Would the money be permissible to use in my business and life

Q: Is it permissible if I start a business doing ads for people? As far as I understand, the ad is digital and does not physically exist. If I stipulate the condition that you are paying for the service of making the ad will it be permissible? 

What is also the ruling regarding buying something, like an ad which is digital, as it doesn't physically exist and qabtha cannot be done?

Q: Is working in a goods and services tax (gst) department allowed in Islam?

What about working in an income tax department?

Q: We have tried to speak to the company that facial recognition is haraam but they continue to insist on it. Will it be permissible to continue working for such a company where we need to use a facial signing in process to log our working times?

Q: There is a profession known as paranormal investigator. In this normally person goes to a place and investigates regarding paranormal activities taking place mostly related to ghosts and haunting places (in Islamic version we can say jinn).

Is it permissible for a Muslim to work in this domain?

Q: I am a student. I teach my aunts son mathematics. This is my first job as a student. I always wanted to earn halaal or I have a wish that my first salary or income will be atleast halaal.

My question is, somehow, I know that my aunts source of income comes from riba or a bank loan or something or fraudness which is haraam. Is my salary halaal or haraam? I am confused. Please explain, if it is not halaal then I will teach him for free. 

Q: My sister recently applied for a tutoring job with good payment online. However, due to being occupied with household chores, she asked me to tutor the kids under her name and profile (without the one who hired knowing) since I am looking for a tutoring online job too. I'm not as qualified as her although I'm qualified enough to tutor those kids but I refused thinking that it would be a deception. Was this act permissible?

Q:

1. Is earning from food delivery (Uber Eats, deliveroo, etc.) halaal, when most of the food delivered is not halaal?

2. What's the ruling on haraam earning in the past which a person didn't have knowledge at the time of earning but when he got to know its haraam he stopped that source of earning? Is the haraam earning in the past permissible to keep, even when he didn't have knowledge of it as haraam?

Q: Is it permissible to have a business that designs invitations for events that are not permissible in Islam, example the business makes invites for birthday parties, engagements, wedding announcements, etc...?

Q: I am a software developer and two weeks ago my friend asked that he has signed a deal with his client for an android app that we need to deliver within 30 days. My friend and his client both are very trusted although the client is a non-Muslim. So what happened is neither he saw the project details nor me and after two week now when I started working on the project I realized that it was a betting app. Me and my friend both are very stressed that should we take the money from this app or not? Since he has transfered the money into our bank account, what should we do?