Install starling withut SIM / mobile number

Due to personal data collection concern, is it possible to use Starling app on mobile phone without using the mobile phone #?

Would a desk line # can be provided (it is company info, not personal phone #) in the Starling admin page instead of mobile #?

Since the mobile app allow QR code to add account, would it be possible to generate QR code per user for them to register their installed app?

thanks.