I've notice there is some MIDI crosstalk right when I start a song. A little feedback leaks through. I haven't dug into the cause.

I don't use MIDI Yoke, I use LoopBe30 and it has an option to "Enable Shortcut Detection". I disable this. The virtual midi channels then continue to work even if a little MIDI feedback happens. I would think Midi Yoke has a similar feature.

For reading midi files, you can open the MIDI file, and it all the MIDI channels go to the Melody track.

From there you can Edit -> "Copy/Move Tracks" to separate out the MIDI channels to separate instruments.

For example, if the Piano is on Midi track 2. Pick the "Copy/Move Tracks"
Source is Melody, clear all except "2", and destination is Piano track.

Repeat this for the other MIDI channels.

Or - I typically just use
File -> "Import Chords from MIDI File" Ctrl-Alt-I

There is many options to chose here, but it will fill out the chords and attempt to separate the Midi channels out to instrument tracks for you. It usually works great for me. Try switching some of the options.

After you're done with either one of these you will probably need to go back and adjust some of the chords that BIAB interpreted from the MIDI.