Is "damage transfer" an actual term used in the game? If so, something like "This attack is unaffected by damage transfer abilities" would easily be an exception.

@CabinetCat You could put that into a phrase like "I'm perfectly fine with min-maxing, as long as it doesn't become conversation topic number one". To me personally, that sounds fairly neutral while precisely conveying your expectations.

@SeriousBri I think with starting the whole additional items discussion, you're already missing mbrig's point. Wizards excel at flexibility, whereas fighters shine at consistently dealing and tanking damage. Both are advantages that are meant to balance each other out. Wizards are horizontally strong, fighters are vertically strong.

"it does not freeze any water." With the exception of Wall of Water, which explicitly states it freezes from anything that deals cold damage.

You might need to use Shape Water specifically on a Wall of Water, as that has the property to freeze when a cold spell passes through, or rule that normal water has this property as well. Also, you'll need a creature (preferably immune to cold) to move around behind the to-freeze water object so you have a target for Ray of Frost.

Side note: This also covers the command "lie" mentioned in the question's text. The target currently can't lie, so the command ends immediately.

Does Zone of Truth even require concentration? From the question I've read so far, I was under the impression it doesn't.

"Zone of Truth is quite literally the only spell or non-background magic (other than Wish, which can do anything) in the game in the category of detecting, compelling, or restricting truth or lies." You're implicitly assuming this was supposed to remain the case when these spells and features were created, which is far from a given. For all we know, there could be hundreds of "you know whether what they speak is truth or lie" spells and features and whatnot, that were planned but have yet to see the light of day.

Also, some of the statements seem to build on the common fallacy that ZoT indicates whether the target is speaking the truth. It doesn't. It indicates at the target's turn whether the target is capable of lying this turn.

The first part is a variant of "lying by telling the truth", which the question specifically discards, although the way it's presented here does seem to render the argument against that moot. Besides, there's no indication the players are the interrogating side. Chances are the asker is a player in a campaign where they're infiltrating an evil empire and this technique has been foreshadowed as a possible challenge. OTOH, if that was the case, I'd just ask them to be creative on their own :-P

You're focusing on purely hostile ambushes a lot. While not wrong in general, the particular situation mentioned in the question, or a similar one, is barely covered at all, because a) there's no oportunity for a surprise moment, as the PCs would just have failed to solve the conflict by talking, and b) the low-level NPCs, in this case, are willing to kill the players if necessary, but would rather not unless they have to.

Honestly, I don't think it needs to be that useless, you just made too big of an effort to nerf it.

Another simple answer that isn't a lie, but deflects suspiction when asked "are you the traitor?" is asking back "why would you suspect me?"

The corpse isn't a creature, but what about the spirit within?

@Mołot That sounds like more of an earlier-editions thing.

"it would cause the creature to be affected by the fire in the rule sense (take damage), which would end the sanctuary spell." Due to the errata, the damage dealt would end Sanctuary, but not prior to it because it wasn't affecting them at casting time.

I see what you were talking in the comments. This takes Lovell's build as a base, but then expands on it.

Besides, I'm not sure if the point of invalid targets for spells actually holds. My interpretation as a GM would be that you still have to target something your character assumes to be a valid target, which wouldn't be the case for the rock (unless you can justify your character thinking the rock is a creature in disguise).