I would assume most gamblers use their laptop anyways.
I don’t think this is true. A lot of gamblers use their smartphones to play and that’s why many casinos have created their own apps because they realize how big this user base is.
I know there is still a lot to work on and improve, but making the website more mobile-friendly should be a priority too.
Welcome to bitcointalk, although I agree with Bitcoin_Arena that it’s still to early to create an announcement thread for your casino as you need to be completely sure that everything works fine before starting your promotion campaign.