Even if it a separate website or not, as long as it is created by the same team, I think it would still be amazing.
How can you be so sure? I do recognize the experience of the Stake team and it is possible that they can add something amazing here, but it is also possible that it might not be a big hit which is why it would be wise to keep your expectations grounded.
I hope they will also have promotions and challenges once they start their sportsbook website/page.
I am pretty confident that they will since that is the primary way to attract gamblers and compete with rivals like Sportsbet and Cloudbet who are dominating in this area currently. Their bet limits also need to be high.