I'm wondering how his death would link into the other books since they rarely seem to have any connection with Batman Inc.
That's a good question. There have been little nods here and there, but it was easy to look at Batman Inc
as its own self-contained thing. (I thought it was easier to read it that way, too.) But if Damian dies, I'd expect the other books (and the March solicitations are certainly suggestive) to deal with the fallout.
The character I'm really curious about now is Jason Todd. The recent reveal in Batman Inc
that he's been operating as Wingman actually makes a few things make sense, like how the Outlaws are able to operate.