[Koha] marc framework and importing records

Hi We're a small school library and don't really need all the fields used in MARC records. But I would like to import my marc records using the import perl script. I was wondering, if I edit the BOOK MARC framework for example, and delete fields that we don't really care about (for example the 00 fields?) will I run into a problem when I import records? Put another way, if I import records all from the Library of Congress for example, using the import script, will the script fail if the field is not defined in my framework? nancy