I am so tempted to write a joke answer to this involving high-speed car chases and envelopes retrieved from dead-drops concealed in plain sight in the shadier parts of town. But I won't. I guess that leading by example is one responsibility you didn't mention. It hurts the community when people break community standards; it hurts more when mods do, so mods have to be extra careful.
Really, the vast majority of what mods do (including most of what you list) is also done by power users. A major exception is handling flags. For the most part, this is a quick and easy job, done a few times a day, but sometimes, it takes a lot more thought and action.
Two other mod duties that are unique to mods and not mentioned above:
Liaising with SE staff. When they have something they need to discuss with representatives of the community, but not in public, they come to the mods. Similarly, when there's something the community needs to bring to SE's attention, it's the mods' job to get that done. Usually, not a big deal.
Dealing with problem users. Thank God, this issue comes up rather seldom here. But from time to time, it becomes necessary for mods to take special action to request, induce, or force changes in certain harmful patterns of behavior.
The parts that are unique abilities of mods are unique responsibilities thereof, and therefore represent a time commitment. For the most part, though, this part of the time commitment is either brief or sporadic, and shared between three people.
The rest is, as I said, doing a lot of meta-work that power users do all the time, albeit with a bit more power (e.g. insta-closing and insta-deleting instead of voting for same, merging tags at will). How much time mods put into that is really up to them. I'd say that anyone who already puts a bunch of time into this sort of work for the community as a power user will probably end up putting in about the same amount of time as a mod, but will have more effect in that time thanks to the extra powers. Anyone who doesn't is probably not ready yet to become a mod.