adding the Scala dependency to the maven build can fix the issue : <dependency> <groupId>org.scala-lang</groupId> <artifactId>scala-library</artifactId> <version>2.10.3</version> </dependency>
No, you cannot do this. The way to do it is as you described. Then, whenever you make changes to build.sbt (e.g., new jar dependency), rerun the eclipse command from sbt and refresh the project in Eclipse so that the newly generated files are reloaded.
Scaladoc is now integrated since release 4.0.0 RC1 of the Scala-IDE plugin. You can just hover over your term, or press F2 while the cursor is on the identifier.