Well, I went through the forum and browsed the 2811 topics... 
These are the ones that appeared to be more in evidence:
- The StrataFrame database, purpose, what it does, StrataFrame Data Store
- Custom Properties, creating, binding
- Deployment of Security
- Changing references on the source code
- How to deal with Addin problems, where to find them
- Activating / Deactivating - techniques to work on multiple computers
- Creating a LaunchForm
- working with the DateTimePicker
- How to deploy pre-released DLLs
- Best practices on setting up Localization, how to embbed the XMLs
- Enable / Disable controls based on State Changed
- Using BBS for reports
- Best practices on Form loading, slowliness
- Setting up Concurrency
- Working with NULL values
- implementing IBusinessBindable into 3rd parties
- setting up ParentXChild relationship
- Solution Preferences overview
- How to set debugging on
- Adding Broken Rules
- Setting up Search Values programaticaly for the Browse Dialog
- Best techniques on retrieving data to populate BOs efficiently
- Possible SF Activation problems
- ShareDataTable and BO translations
- Properly creating working environment and source control
- Techniques to work with mobile devices
- Ways to deal with connection strings
- Business Objects on Web Applications
- Creating global variables
- changing DataSource at runtime
- Using Link Tables
- Working with Grids
- How to setup the Enterprise Server
- Changing strutctures in DDT without assigning a default value problem
- Database Migrator use
- Retrieving Current User informations
- Populating ComboBoxes, top most, etc.
- Creating and dealing with User Controls
- Creating templates
- Comments on Software Deployment techniques
- Best practices on NameSpace structures
- ways to work with pictures and how to store them
- Attention to applied filters on BOs
- RBS in a web application
- SF and AJAX
- RBS in a non SQL Server environment