Valid & Invalid transactions

Q: I am seeking guidance regarding a matter related halaal and haraam. 

I live in the United Arab Emirates, and we are not very well off, we struggle at times to buy things apart from the necessities. 

There are two fintech companies TABBY AND TAMARA. 

Tabby was shariah compliant initially when they started, splitting each bill into 4 installments and so was tamara. Tamara is still 4 installments. But tabby has now introduced installments in 6 months, 8 months and also 12 months and when they started here, there was a fatwa on their website too, they don't say that it is interest, there's an extra amount that they charge which they call processing/service fee, I want to know is that interest? I have multiple payments spilt across because I did not know it and just realised it, also because initially there were fatwa on the tabby website. For tamara, there is also a fatwa and they have mentioned names of scholars who have given fatwas 

All of the shariah resolutions are attached on their website too, so I want to know if what they calling the 'Processing fee' is not interest and allowed for me to use as it is really helpful, and if it is not, then I have multiple payments spread across both companies and I am not in a position to pay it all off as we struggle big time financially. As someone striving to act in accordance with the teachings of Islam, I want to ensure that my actions are pleasing to Allah Ta'ala. 

Q: What is the ruling regarding online trading - day trader. He trades with various things like gold, currencies and oil.

Q: Recently we see maktab jalsahs being held and you have to purchase a ticket to attend. Is this allowed? 

Before we use to go to jalsahs without having to buy a ticket. Tickets are sold for R50. 

If the maktab can't afford an elaborate jalsah, why have it elaborate or if its difficult then should they have a jalsah?

Q: There is car company and they are selling their cars in the following manner: 

I pay a certain amount of the total and they give me the car but they don't transfer the car to my name. Then, after I pay the 9 installments, the car will come into my name. In the meanwhile, they ask me to take an insurance policy for 9 months to cover me from all risks in case something happens to the car. Is this type of deal correct?

Q: I would like to know if buying a box with the contents being unknown permissible or not. Example there are 5 closed boxes you cannot open before buying but the estimated value is R100 each. It can be worth more, it can be less. If the estimated value is R100 and it's on an auction platform, the bid can land upto R800 example or can cost you R100. 

Is this permissible to buy? 

Please note that each box will have something and none will be empty but it can be something with very low value. 

Q: Is it permissible to renegotiate a business deal that one had previously agreed to but had not considered the consequences thoroughly?

Q: I wanted to find out a fatwa regarding weights and measures in my business. 

We are steel traders. We buy steel a certain thickness say 0.2mm but the factories that produce it can’t get the exact thickness due to the production process. So the thickness varies from 0.195 to 0.205mm, sometimes more sometimes less. 

What is the ruling on this because we sell the product as 0.2mm. We sell as per the thickness that we order. We don’t order a lower thickness and sell as a higher thickness. This is purely a production tolerance level as the machines can never get it exact.

Q: Is it permissible to bypass an estate agent in purchasing a property? 

Example, I see a property for sale on their website/see their board outside the property. I then go directly to the seller and do a private deal with them, to avoid getting the estate agent involved and to avoid paying them commission. Is this permissible?