SQL Server 2000 to 2005 Data Migration

1) We have OLTP DB on 2000 & OLAP DB on 2005.

2) We have decided to use SSIS for migration and interface is BIDS to develop, build, deploy & install SSIS packages.

3) Initial full migration is simple with column mapping and queries.

4) Incremental nightly scheduled migration is based on datetime value of source table column versus datetime value of end of most recent migration.

5) Inserts, updates and deletes are allowed in source. Whatever is updated and deleted in source I am finding the PK's via query compare via linked server in stored proc & deleting all these records from target all this in stored proc.

6) Now I have to pass these PK's along with inserted PK's to select statement of SSIS package against source to insert into target.

7) We even have to encrypt some tables colmns data while reading from source so that it is secure in network and gets into target database as such requiring decryption for reports and front end display.

8) Is my approach okay? How do I pass the PK's to SSIS package SQL statement. How, where and when do I fit in encryption part.

9) Are there any better ways that you can think of.