2
yes, that normal, since the upgrade script don't work for RC.
RC should not be used in production environment.
To be sure, you have to compare the MySQL statements in the install directory, and sql repository for the 2 new modules (if you make use already of them).
As long as i can remember, there are no DB changes between RC2 and final (if there is,it's about group tables), but it's always nice to check
Do synergy or die.