I found out the hard way that you if you delete a Build Profile from the vRO method, it will happily delete it even if it is in use by a blueprint. However after doing so the blueprints that had that build profile attached to no longer are editable, instead you get the vCAC Infrastructure Service Unreachable ( REPO404 ) error. There is an unhandled exception on the query thrown in the logs, which I am assuming since it can't find the link to the build profile.
This is with 6.2 vra and 6.0.3 vro.
Only way I have found to "fix" it is to delete the Blueprint, which you can't do until you delete all machines that were provisioned with it. Since I am in a lab environment not a big deal, if I was in the production environment it would have been a real big deal...
Either vRO should automatically disassociate the build profile from all blueprints it is used by, or it should stop you from deleting it warning you it is in use.
Tim