Dear Gerd,
I don't see any problems in the database dump. Can you try removing the Views plugin and uploading it again? Sometimes an incomplete upload can cause strange problems like this one.
About the Custom fields control, this is expected behaviour. When you delete a field, you are only deleting the field definition in Types. The actual data stored in the postmeta table is not deleted.
Please let me know if you are satisfied with my answer and if I can help you with any other questions you might have.
Regards,
Caridad
