@lassi.liflander can you elaborate on example how you’ve seen the objects not within the spatial hierarchy? As you know there are many ways for this to be incorrect in IFC 
It’d be good to see an example of the second mistake, as I haven’t seen this one before.
As for GUIDs, I’ve raised that the spec description of GUID generation doesn’t actually describe the current state of affairs. The GUID generation as currently implemented disobeys a lot of industry standards. It is not surprising people make mistakes. Perhaps this should be resolved: