The default EB settings are definitely very reflexive, I've had a game or two now with EB lit off the first plunge, hah.
CIU lights the feature to count as shots for a song, e.g. Same Old Song + Dance CIU lights all of the Aerosmith targets for shots. Great to bring into MB, it goes straight to Super Targets when it's complete.
The left inlanes can be toggled, but not the right inlane.
Does the lock bar button do anything besides abort MB? I thought it might be the standard free shot, but I haven't seen it work and am not sure how you'd light it.