Yes, websites will be a thing of the past. Mobile apps will be the only way we use the internet
Yes, however every website that is still used will be responsive to fit any sized screen. Unresponsive websites will be rare to find
No, desktop websites and mobile apps will be used as often as they are today
No, mobile apps are a fad. Websites have been around for decades and will continue to stand the test of time and will continue to do so.