> Enable branch protection for master, so that only pull request that are green on CI and have been reviewed can be merged.

Is that functionality available within Bitbucket + an external CI somehow?

Our workflow involves branching off of master at all time. Staging server can be wiped at any time, we have multiple staging servers. Production code can only rebase with master (or release branch); depending on the client we also have a release server as well which rebases with master and then into production.

Works well so far with team up to 5 developers....haven't tested it out further but wouldn't anticipate too many issues.