The first article provides solid and practical assistance in getting the most out of SQL Server CE 2.0. After a thorough walk-through of the SQL Server CE Query Processor, it shows what steps can be taken to optimize application performance. The second article is simply a "must read" if you are planning to deploy SQL Server CE 2.0 and use the built-in Merge Replication or Remote Data Access methods. Even though Microsoft has done a great job in simplifying setting appropriate security settings, you are better off if you also really understand the concepts.
Having just successfully implemented an RDA pull solution for the exhibitor lead retrieval system at Microsoft's IT Forum I totally agree that the second article is essential reading. You must have a really strong handle on all the security issues.