A: yes this is doable for sure for at least 75% of the flow, the only thing we need to test is the login to the backend of booking.com if you can submit temporary credentials via secure ticket we could do some tests and confirm: https://rtila.com/support
otherwise this should for sure work with our new V7 coming up in few days where we have new integrations/compatibilities with Brave and Incogniton where you could have your booking.com session created and RTILA Automation will be able to piggy back on that existing booking.com back-end login session