With regards to the midi data, the BSP doesn't echo all midi in data on the out, only the channels you have assigned to the three sequencers and only the note values, velocity and key on/off data. And only if you are not recording. Not sure if it echos aftertouch.
The midi in port is really only good for programming the the BSP. I use a midi merge box to bring my BSP into my midi chain and have an old midi controller keyboard connected to the midi in of the BSP. It's so old, all it has is the keys, 16 buttons and midi out, but it does what is needed.