You are right, these problems are observed with the current implementation of the schema explorer. Our plans are to migrate this toolwindow in one of the following versions to the newer implementation used in Model Object Explorer, where the problems with multiple selection and autoscrolling are already solved. For easier navigation both toolwindows are supplied with a search toolbar but your idea for navigation when a button is pressed is also very good and we will have it in mind for future improvements.
Thank you for your feedback!
OpenAccess ORM Q2 2013 brings you a more powerful code generation and a unique Bulk Operations support with LINQ syntax. Check out the list of new functionality and improvements shipped with this release.