SharkyAfsar

All files shown within Affinity Designer are inside the Affinity Designer sandbox, stored on your iPad. You need to save each document separately by pressing the 3 bar hamburger icon and choosing save. This will save to the Affinity Photo folder in iCloud Files with your current settings. To free the space up in the sandbox you must press close on the hamburger icon after you have saved each file.
You should also be aware, the sandbox is only a convenient location while you are working as this is where designer auto saves your work.  But, if you ever had to delete the app and re-install you would lose everything in the sandbox so do not leave completed work on the home screen, save it to a cloud service or in the On my iPad folder.

Hey guys the above works, I exported the design file as pdf and kept the option as 300 dpi and 450dpi for anything images above 450dpi. 
And opened the file in Adobe illustrator and the images were 300 dpi. I guess problem solved. Yeeeee

Not directly (copy/paste won't work). You can open an .afphoto file in Designer. You could export a slice and import that into Designer.

Hi Damien
 
When you choose a studio for example brushes, choose a brush and start working on your image, the studio automatically closes to give you a bigger view. If you activate the pin, the studio stays open.