Vomiting abuses AStr and LStr. haven't you ever gotten the message " Youreleft/right arm/leg feels weaker" after puking? Thats why after I pray to mellis for school food and then eat it to boost End I immediately pray to Seges to cure the poisoning.
I kill dwarves all the time by throwing highly enchanted whips that mistresses drop 9or whatever else is on hand. Whips that are unbelievably accurate rarely miss.
I save them until i know what will be most useful to wish for. Eg. If i got the SoW and then immediately wished for Vermis and then found two more on the next two levels that would be a wasted wish. I'll usually use them on wands of cloning or scrolls of charging for wands of cloning/mirring once i find a wand with 3 or more charges. If i find a 3 shot wand early and have lots of charging scrolls then i might wish for a key piece of equipment like a helm of brilliance or boots of agility (in the rare case when agi boots don't spawn).
its says the severed head disappears - i think what happen is your wand of mirroring shattered creating a mirror of you that was promptly killed. only mirrored stuff, non perma angel equip, stuff from the sneaky chests and golem parts disappear like that
carry a bunch of bones and all the canines will be your buddies - puppies, jackals, wolves, and blink dogs. pray do dulcis or use the lyre and you will have even more friendlies, use a wand o necromancy for friendly zombies, or tame a necromance for hordes of friendly zombies and skeletons, not to mentions mistresses, angels, and friendly fountain spawn (spiders, snakes, rats, dark frogs of all sorts, slimes, and even the odd dolphin).
Given the above I don't really think friendly randomly spawned creatures are necessary.