[Koha] help for a friend

[Nicole Engard]

I have a friend that is new to Koha and I've been able to help up
until now - so I thought I'd turn to you all for help.  She's having
issues with rebuilding authorities.  She's on version 3.0.5.  She
follows these steps:

1) Export records from our ILS and use MarcEdit to get them like Koha wants them
2) Use bulkmarcimport.pl and bulkauthimport.pl to load records
3) Run link_bibs_to_authorities.pl
4) Run rebuild_zebra.pl

Two problems with authority linking:
When I'm done with these steps, I can see all loaded bib, item, and
authority records in my system.  And, some (but not all) of the
authority records are linked to their related bib records (problem 1).
 But, when I try to do an author search on a name in an existing
authority record but not in one of its linked bib records, no results
are returned (problem 2).

And a tertiary problem:
I've discovered that some of my records contain errors that cause the
bulkimport scripts to fail.  I think, but am not sure, that this is
related to non-Roman characters in the records.  Two questions related
to this problem:
1) Is there are trick for identifying these records before I actually
try to load them?
2) I made the dumb mistake of double loading about 8000 authority
records because I forgot to rebuild_zebra after my authority load
script failed.  Is there a good way to do one of the following:
       a) Batch delete all authority records with no bibs attached.
       b) Batch delete all "duplicate" authority records.
       c) Wipe out the entire authority table and start from scratch.