Also, how can I provide a tf prefix for the /robot_description parameter? Now, my Robot Model in rviz doesn't display my robot because of this error: "No transform from [base] to [/worldBase]".
In cturtle you set the "TF Prefix" option in the RobotModel display. There was no per-display support for it in boxturtle, but you can set the ~tf_prefix parameter on the rviz node.