As for resources, Behringer's feedback destroyer (BFD) has been a favorite among subwoofer tweakers for years now - I never investigated them closely, but have seen numerous discussions of them in places such as HTF. One recommendation is the BFD Guide site (formerly called Snapbug, since that was the old domain name), which some consider the definitive source for BFD information.

Finding a way to tap the analog signal internally, pull it out to process it externally, and then plug it back in would be a pretty major undertaking - I suspect that Outlaw would be leery in the extreme about coughing up information like that. It would probably qualify as a case of "if you can figure it out without asking and don't care about the warranty go for it, but otherwise forget it." As for the IR-controlled 7.1 analog volume control, I have no idea. Folks have suggested that Outlaw (or somebody) build a purely analog surround processor on occasion - mostly as discussions of ways to improve the ICBM, such as adding multiple inputs and/or volume control so it could act as a 7.1 switcher or even a 7.1 analog pre-amp - but I don't think anything has really appeared on the market.