Bass on the LFE channel on SACD and DVD-Audio discs are mix dependent. In other words, it varies from disc to disc. Some have it, some don't.

"cinch" I have no idea what you mean by that term. Please explain.

Sure. That's kind of what it's made for. Pick the crossover levels for all of your speakers and send the bass to the sub. The question becomes why use an ICBM with a 990?? It's my understanding that the 990 includes most of the features you would get from an ICBM. The 990 would also apply these features to the balanced outputs you seem so concerned with.