As far as getting AOW, depending on your personal comfort level with deep and night dives, you might benefit from it, although it's certainly not required. One thing to consider is whether your dive insurance has limitations of coverage if you are diving beyond your training level in the unlikely event you are injured while diving. If it does, and it's demonstrated that you exceeded your training, they may refuse to pay the bills, in which case you'd be wise to get the cert so that your coverage would be in place for any eventuality.
