Items casting spells and their weird effects

A map I recently tried had an item that casted rejuvenation on its target which, when I checked the source, indeed had rejuv as its item ability. This got me thinking, and so I tested this effect with four different spells.

Four usable items, all with 3 charges, actively used, perishable, etc. Indentical except for icon, ability, and custom item based on...

Blizzard (Neutral Hostile) [cheese]
Bloodlust (Neutral Hostile) [spiked collar]
Raise Dead (Neutral Hostile) [spiked collar]
Firebolt (Neutral Hostile) [spiked collar]

The results were as follows:
Blizz - The item asks for an AoE target point, but only casts 1 wave of blizz. Takes full blizzard mana as well.
Bloodlust - The item is neither usable nor droppable.
Raise Dead - The item is neither usable nor droppable.
Firebolt - The item asks for a target, then casts firebolt on it like normal. Costs its full 75 mana too.

What's blowing my mind is that lust and raise dead are unusable, I can neither right-click nor left-click them, to use or drop them. And the item it's based on is no help either, Cheese works just as well as the Spiked collar.

I will continue to test this, if anyone has some further insights please comment.

If anyone remember the awesome RPG princess prophecy, the same thing with the blizz happened there. I think that normally we can't change the mana drain (after all we can't normally edit spells). With changing some txt files it probebly works (I didn't try yet).

Try other unit abilities that are based on Hero abilities like Death Coil(Neutral Hostile) or Rain of Fire(Neutral Hostile). Could be the normal unit abilities that do work with Items used to be Hero abilities. While abilities that aren't coded as Hero abilities may not work with Items. If you look at scroll of protection, the icon above the head used to be one of the Crusaders(alpha) magic Seals.

This is just a guess, but it seems to be that way.

It may not work with spells that are autocast.