I haven’t done any work on rosbag or playback, so that is entirely unimplemented and not working.
As for not using the bridge, you can run rviz using ROS 2 and make use of several of the plugins to avoid having to pass data through the bridge. Some of the interesting working plugins are: tf, laser scan, map, and robot model. Others (odom, path, point) may work but I have not tested them.
Note that to use the robot model plugin it requires a change to the robot state publisher to publish the robot model (see this branch). I just created a PR for these changes.