Concerning the miscellaneous items, there is a problem that I think needs addressing. It's the combination of two factors: slow recharging and not being particularly unique.
Slow recharging means that you aren't going to use them very often, because you can't control when they will be available again. Not being particularly unique means that, in a given situation, there generally will be other stuff you can use instead, and so you will use the other stuff (unlike the important potions).
Maybe it's just a mindset problem with me, but that's how I play with them. As a result, I almost never use them.
Enter the crystal ball. On one hand, it's very dangerous to use. On the other hand, it has a use for a specific kind of character, and there is no other item that can cover for it. So it's useless for 99% games, but there is a very small area where it's a real game-changer (a Cheib PC that can survive without MP, but can make good use of them). The crystal ball has no usage limit or cooldown, as far as I can remember.
So I'll make a short list:
- -- Items that grant allies: Horn of Geryon, Sack of Spiders, Phantom Mirror, Phial of Floods, Lamp of Fire: these compete with the scroll of shadows, and I would only leave three: the mirror, one between the bag and the sack, and one between the other three, because they are just too many, and part of an excessive abundance of ways to obtain allies that affects all of Crawl. If you think about it, the fact that lots of gods grant allies (even to non-casters!) disincentives you from using any of these. And those who really, really want allies have a background and a whole magic school they can choose. Water and Fire could probably just be removed, and the bag too; the Horn is a reward, but I wonder how much use it really gets. Maybe turn Horn, Fire and Water into a set of fixedart armour.
- -- Direct damage: the Lightning Rod. Since it's just damage, it competes with any other killdudes.
- -- Move Other: Fan of Gales. It doesn't really have much competition. I would move the lightning rod's 3 charges mechanic to this one, and remove the rod, so that the fan's use is incentivised by reliability.
Concerning wands:
- I would remove enslavement and polymorph. Paralysis does everything the other two do (I have never used enslavement to gain an ally, only to remove an enemy).
Ugly creatures could react to any spell thrown at them, instead of just wands of polymorph. - As said, digging can be fused with acid.
- I would keep flame because of how clearly puny it is. It's like how you stop carrying clubs after a while.
- Scattershot is cool because it's the only wand you want to use in melee range. Clouds is cool because you can use it with vision blocked. Disintegration is cool because it just feels different. Iceblast imho feels a lot like Disintegration, but it is used a lot (by me at least). Random effect also objectively gets use.
This way, wands would go from 11 to 8.
I like the idea of idols that you can't take down the stairs. I think that there could be some fixed skill thresholds, like 14 evo you get 2 uses, and 22 evo you get 3. The only problem is how it would interact with shafts.