Dave,
Some quick thoughts:
AAR itself is not potentially the most significant issue with respect to the loss of 230. The ignition source (hot pipes) were the most significant issue, and stem from decisions made long ago (pre 82 I think).
I may have this wrong, but the main issue with AAR seems to be that the system - system issues are not fully understand, there have been some strange occurances leading to leaks, and on that basis, even though there is no longer a clear/obvious ignition source/risk, it is not being cleared. It must be remembered that leaks on ANY aircraft are not categorised as "improbable" and hence all aircraft designs should be able to tolerate leaks. Even new aircraft that only leak rarely, still might leak - and hence to be safe must be immediately imperilled by such leaks. Despite this, the decision to suspend AAR is perhaps understandable.
The issue with the rigour of the safety procedures is that they were infact not as good many years ago. Things have moved on and analysis techniques, faliure mode understanding and processes now are much much better. The interesting issue is the fact that increasingly "better" approaches (including the adoption of saftey cases) have failed to spot problems that have haboured within this legacy system, without biting for many years. It is likely as you say that the "its been alright for years" mindset may have degraded the rigour with which more modern, best practice analyses have been applied. This is actually a human factors issue - its human nature - optimism bias if you like.