Biblically speaking, the line between what kind of behaviour excludes one from church participation and what kind of behaviour does not falls somewhere in this grey area.
And even at that, the one who is excluded is so treated for the sake of his eventual inclusion.
Conclusion: Churches don't have boundaries for the sake of labelling people as "in" or "out", "saved" or "damned". Boundaries exist for the sake of holiness - the holiness of those who participate in the body of Christ and the holiness of those who do not.
The church as a holy people must make those who are not the church aware of their need for holiness. That the church as a holy people can include those steeped in such unholy professions as prostitution and banking completely confuses things.