Well, it could be fun! There are manga out there that focus on surfing and showcase the thrill and challenges of it. You might just discover a new favorite if we give it a shot.
Yes. One option is to collaborate with brands for promotions using the manga characters. Another is to publish digital versions for sale. Just make sure you have the proper rights and permissions.
I'm not sure exactly. It could be that 'We' refers to a group of characters in a particular manga or maybe it's about the creators of manga. Hard to say without more context.