Inventory decisions are only busywork when they're obvious or don't have meaningful consequences. Trivial, obvious combat is busywork too.
Sure, but the way ID works for scrolls in crawl, it is busywork. It has meaningful consequences if you forget to do it, in the way that failing to fill out a TPS report does, but there's essentially an algorithm for ID'ing your scrolls with minimal waste on average and whether you get screwed doing it is a matter of luck and not that important usually. Brogue does not sound wildly different from the scrolls perspective. You have some idea of how many of various things you're expected to have and you base your use-ID decisions on that. Whatever.
Crawl's hunger clock isn't 100% pointless like Angband's is, but it's still pretty minor. You can and should rest to 100% health in between most fights and there's no real cost to backtracking through the entire dungeon. Crawl's hunger clock does not force you to think about how you will solve the next fight as you engage in the current one. It keeps you moving and it doesn't let you grind indefinitely, which are both good things but other games have better hunger clocks that do much more than that.
Yes, if you even slightly know what you're doing, hunger is not a real issue in Crawl. Time and resting is an issue if you speed run though, and since online competitive play is a thing in crawl and crawl has a sensible scoring algorithm that takes speed into account, this has a nontrivial impact.
I'm 100% in favor of multiple "levels" of victory, but hunger clocks are so important and so beneficial that they should be a big factor in even the easiest version of any roguelike.
Well, I think we can agree on the "clocks" part at least.
re: trivial, obvious combat is busywork too: That's an interesting point, but I don't know of a good proposal for addressing it, other than autofight (which is a decent solution, imo). If you have a system in which monsters generate independent of the player's actions and the player increases in power consistently thoughout the game, it seems to me that there's no way to avoid trivial combat without also making combat a pain in the ass -- e.g. by overly complicated tactics.
One way to go that springs to mind in light of the discussion here is that monsters spawns can be tied to the game clock. This is what happens in crawl in a limited way, but it could be applied much more aggressively.