Basically, if you pick up a consumable item in combat and accidentally click on an enemy in an adjacent tile, they will... um... consume it.
Not really. It is slightly counter-intuitive for people not used to it, but it's pretty standard for rogue-likes to have that sort of thing - if you can use something on your allies/pets, you can use it on monsters and the effect will remain the same. And honestly, it's the same with spells - whether you use them on monsters or your summons, the effect remains the same.
It gives Vampires something to do with their food, by refilling the enemy's blood. And yeah it can be nice for pets; during a zoo I'm perfectly happy to toss a sandwich to my Dragon so all my booze is going to Fireballs rather than resummoning him. ...And actually, I assume you could get an Octo drunk now to reduce their Bonus points if you use Dwarven Gut Rot for the extra debuff.
Not so much, but I wasn't sure if it was a bug or an unintended feature. It's kinda easy to give a monster a consumable item if you use the mouse for the majority of your control system, as I do.
Now I finally know what to do about all those low-level alchemy acids. Hmm... The description specifically says not to put Acidum Salis on potatoes.
Wait, wait, wait. Does this work with potions? I am specifically talking about Aqua Regia/Vitae/Fortis and Acidum Salis.
Bonus points if, after you feed/booze hungry and thirsty diggles, they revert to regular ol' diggles.
...Or it stuns them for a number of turns equal to the item value. Gotta digest... And gives you options/control over which item they "take".
Half-confirmed. This would be awesome if the effect of what you fed the creature applied to it. (And not game breaking at all, as very few items are especially bad for you, one rare root being an exception). However all it does is make the item disappear. No healing, no addition of voltaic damage to enemies, etc. I hope they do implement this. These little, middling details are part of what make roguelikes so much fun. (You'd have to prevent mini-bosses from transforming due to diggle nog, or reduce the duration to something like one turn [ideal], however they already resist transformation based skills, so that seems perfectly doable.)