Fix malign gateway not registering its terrain change.
Fix lava orcs in water spawning steam in nearby walls.
Remove a special case that didn't appear to do anything

Since you die at <= 100 hunger.
Increase the cost of scrolls of immolation slightly
Don't trigger backlash effects when failing to rebrand a weapon

Really the scroll should just abort without being used up.
Allow aborting the staff of Olgreb's OTR without wasting a turn

For example when allies are nearby and the player is prompted to avoid
poisoning them.
Fix Mephitic Cloud and Poisonous Cloud never prompting when aimed at self

Spells with SPFLAG_ALLOW_SELF are sometimes useful to aim at the player's
square, but that doesn't mean that they should do so with no prompt, since
they are still more likely to be harmful than not.

The ALLOW_SELF flag now just allows such spells to be self-targeted (with
a prompt) even when Options.allow_self_target is set to CONFIRM_CANCEL.
Currently the spells affected are Mephitic Cloud, Poisonous Cloud,
Freezing Cloud. Other AoE spells like Fireball, Fire Storm, Ice Storm
might feasibly be self-targeted but these seem significantly less likely
to be used in that way.
Remove the reaching brand

It only appeared on whips, so was hardly ever relevant. Reaching as a polearm-
only effect works just fine.
Allow querying \ screen when reading scrolls of identify

Somehow this only worked when the scroll was not identified before.
Always identify wands on zap

It was easy but tedious to reliably identify any wand with the strategy of
"zap a hurt, low-MR natural monster that's standing in front of a wall".
Identifying after one zap keeps the slight tradeoff of using up a charge
if you choose not to scroll-ID. Monster zaps still have to have a visible
effect to be identified, potentially this could be changed to always ID
after seeing a zap too (and then beam.obvious_effect would no longer be
necessary?).
Don't place additional webs over time in Spider

There are more than enough between the initial amount and those from
jumping spider attacks. Placing even more over time makes autotravel
through the branch much more difficult than it needs to be.
Reduce Shadow Creatures summon cap, don't cap band members

Band members already have a very short duration, capping them along with
the band leaders results in the entire pack getting capped and timing out
immediately.
Rework the Elixir card

Restore HP or MP over time (10% of max HP/MP per turn for a variable
number of turns) instead of instantly.
Power 0: restore HP or MP on a coinflip
Power 1: restore HP if at <50% HP or MP otherwise
Power 2: restore both HP and MP

Still fully restores HP and MP at power 2, but over 10 turns instead of
instantly.
Adjust Song of Slaying

Randomise (and increase on average) the duration, reduce the power cap
to 100, and slightly loosen the requirements for monster difficulty
(each monster difficulty tier can provide 1 more slaying than before).
Fix noise display in Song of Slaying description (#7627)
Remove Song of Shielding

Just mimicking guardian spirit, even if it works a bit differently, isn't
very interesting, and it appears to not be useful anyway. It's also
inconsistent in terms of not behaving as a "song" in the same way as Song
of Slaying (and making the two songs exclusive would make it even worse).
Rework the slow healing mutation

Levels 1 and 2 halve and stop your natural healing respectively, but only
when hostile monsters are visible. This should make resting in safe places
less annoying, while giving the mutation a noticeable effect when in
combat.

Level 3 is unchanged, as is the mutation's effect on stat drain recovery
(slowed by 1/3 per level).
Fix a dryad simulacrum crash.
Remove reaching from weapons when upgrading saves; misc cleanup.

The brand merely got its name hidden, resulting in strange results in tiles
and wizmode.
Likewise, remove orc slaying.

Such weapons retained the brand, yet it did nothing.