From your stats I take it you do use herbs quite a bit - at least morgia on this char, no?
For avoiding deaths like this one I would suggest a few precautions (which you may, or may not already use):
1. Use 'w' command when walking around, rather than simply pressing the appropriate directional button.
2. Always have your tactics set to "coward" when casually exploring - I learned this the hard way; hidden opening + ghul = chain paralysis death.
3. Use the 'l'ook command often - if you see a new, suspicous looking foe you can simply look at him and press 'm'ore in order to at least know his speed.
As others suggested for damage output - piety! There are some really nice artifacts out there who will really help overcoming this problem. Also, I suggest you stock up on stomacemptia herbs as they can be very valuable when encountering a vault of ettins/giants of different sorts - though some may consider this last mentioned tactic a bit scummy.
Anyway I'm not sure how helpful my advice is, since you seem to be a pretty advanced player having beaten the ToEF and all. Best of luck to you!
Suddenly a stream of acid pours down from the ceiling! The cute dog is horribly mutilated by the acidic fluids! The cute dog dies!