Hi,
Speaking with our deployment team, they advise customers to use MDM deployment to disable all other browsers on the system with only the CWS Mobile Browser being the available browser. Setting the default browser on IOS isn't done within the CWS Mobile Browser app itself but will be done within the OS. As far as I understand, there is no option to select a specific default browser, hence the solution being to lock down devices so that other browsers are not allowed on the system.
With regards to your second question, the CWS Mobile Browser is a standalone app, there is no way to integrate the technology into other browsers.
Regards,
Brett