You've got a great example of how to do a UI for sites and bindings in IIS. I'm not sure why SM hasn't followed the same pattern. IMHO the domain and bindings being separate in the SM UI is not ideal. I suggest having a list of sites like that in IIS and that actions you can perform against the site down the right column and allow me to set bindings for the site from the domain and not a separate area. Again, there is a proven UI for how to do this, SM should consider following the same pattern that IIS uses that admins are also accustomed to.