database schema synchronization

Hello, i am going to maintain any machines with maxdb and synchronization in production, but i am still changing applicacion schema because i am still in development so i will need to be able to change the database schema to the machines in production to newer versions of the database, i am maintaining a catalog in my applicacion subversion repository so i can do diffs between versions, but i have two questions:

1.- I have to stop synchronization when i am going to do schema changes, no? if i have to do it when i reactivate replication units if table columns have changed, do i have to reconfigure this replications units?

2.- any utility to do a visual/easy database comparator and synchronizator of schema? i have found many utilities to do it with SQL Server or Oracle but only one that can work with any odbc database (i have not tested it yet but i am doing to do anytime soon, http://www.dbbalance.com)