Navision Financials SQL Server Development

I am currently writing Stored Procedures and Trigger code in SQL Server 7.0 responsible for creating records using replicated data from an external SQL Server 7.0 database, and then inserting the records into related Navision Financials SQL Server tables. I am wondering what the impact is, if any, of changing the Navision SQL Server fields to accept Null values (not the primary key fields of course) so that I do not have to write needlessly long INSERT statements in my SQL Server Stored Procedures and Trigger code. Any advice would be appreciated! Thanks, Andy Sandefer