Required documents for UAE residency?

Hello, I am planning to work and live in Dubai by opening a company in UAE ( Mainland, NOT Free Zone) and I just have a question about the residency and Emirates ID required documents.

I hold the Belizean nationality but I am born in Syria and both of my kids (23 years male and 25 years female) are born in Syria as well and hold the Belizean nationality  but we don't have the Syrian nationality right now but just our origin is Syrian and I am wondering what are the required documents for this case regarding the Emirates ID and Residency? and if there is any application I can see online?

Because I read that anyone who has Syrian origin regardless of their current nationally requires extra documents for the residency so I am just wondering if anyone can advise me what extra documents or requirements I need or could be asked for in order to prepare everything before going to Dubai according to your experience or anyone who has a similar case compared to mine?

Thanks

There are actually no extra documents required for the Emirates ID or residency process.  With your birth place, the issue that will come is the initial security clearance when you set up the company.   That may end up being rejected and there is no process to appeal it or to find out the reasons why.    However, if it is approved, the rest of processes will flow as per standard.   At that time, if you apply as an employer for your visas on your company, you will be able to see the process flow online but it is a limited view.

And do they reject often or are there any common reasons for the rejection? Or some tips?

Rejection is quite common.  And no one gives reason in any security clearance rejection :).