Lighter weapons give you more attacks, making Octiron dagger +11 or above (44g, unbelievably accurate, almost unbreakable) the best weapon.
You can't change materials to liquids or any kind of flesh but banana.
You can't detect dark frog blood or flesh.
One time, I kicked a chest in the post-Elpuri dungeon and it said "You shudder." There was no altar there or any reason for shuddering.
Phoenix feather is a good conductor, so it will rust easy and lightning will go through it (blowing up wands in a chest) or destroy it (melted legs).
Making your limbs into GEF boosts your danger level way more that Phoenix, and combined with good equipment and HP, will make Ischaldirch spawn.
For the ultimate char, use fountains to get permanent Haste, Teleporting, Invisibility, and Polycontrol.