Does your Remote SL keyboard have a built-in sound engine or is it simply a midi controller? If it has no built-in sound engine your need to insert a software instrument on the track to hear sound, or route that track to an external Synth, Sampler, or Sound module that does produce sound.
It's simply a MIDI controller. I've inserted a software instrument and it will produce a sound, but only on the piano roll or if I select direct input from the MIDI controller. It doesn't seem to work when I use the Focus mapping to select the controller.