Schengen (Belgium) Visa for Bangladeshi Citizen & Resident

Hello, I am in the process of helping my relative in applying for a tourist visa to Belgium.

I know that the following is required:

- Application form (Complete)
- Family details form (Complete)
- Passport (In posession)
- 2 x photographs (In posession)

- Proof of purpose of visit (hotel reservation or organised tour booking etc) (Can he use only organised tour booking or will need both? He doesn't want to pay for a hotel in case he doesn't get the visa)

- Evidence of occupation/student status - bank statement to show funds & maybe employer information (He owns a business in Bangladesh, so what would he need to show? I'm assuming business incorporation certificate, bank statements and any tax information. Please correct me.)

- Valid travel insurance covering a minimum of 30,000 Euros (In posession)

- Flight booking (Does this need to be paid for and booked or can it be just a free seat reservation through an agent? He doesn't want to lose out on any money due to denial.)

Also, could you please tell me if there is anything in addition he should provide that can make his case stronger? Is there anything I'm missing?

Thanks in advance!