You can go through  a recent article named GCC review- Brexit A blessing  or  a curse which will answer many of your queries

Dear Shouvik,

I think it is a big asking. The effect of Brexit on GCC, as well as the world economy, is at best non-straightforward. There is concentration of UK markets (only political), frozen financial markets (high contagion for markets heavily interlinked with the UK and EU economy), increased costs of trade in the medium term through renegotiation of new terms of entry. 

However, you need to contextualize this concoction in the specific nature of GCC international exposure through oil exports (do they rely more on the UK and EU market?) and global socio-politics. The effect may be larger for some countries than others in the GCC (I ain't a specialist in the GCC politico-economy) depending on exposure to regions that are bound to suffer greater ripple effects due to Brexit .

This needs a holistic view.

All the best,

Muthoka SILA.