Basically all what's on your list
@Noodler except for:
Emergency whistle - my ABS backpack has it on chest strap, so no need for extra
Sunglasses (for the up) - most of time I don't bother
Sunscreen stick - never really needed that, except for once it would be cool to have it. But in general I'm out enough to have such tan, that most of people don't have it in middle of summer, so no need for sunscreen
Hand warmer packs - never. Don't really feel that cold that thick skiing gloves wouldn't be enough.
Carabiners - no need for that. If it doesn't fit in backpack, it doesn't go with me
Ski Multi-tool - not really, but I have torx T20 with me in case I would need to tighten something on binding (never needed until now)
Microfiber cloth - no need for that. googles bag is good enough if needed to wipe googles
Flashlight - only on early morning or late afternoon tours
Lighter - nope, I don't smoke
and up in mountains when you are above forest level and have only snow around, it wouldn't help much either
Small roll of duct tape - wrapped on my pole. It does come handy here and there
Skin scraper - there's something you carry with you anyway, and does job good enough.... ski
Skin glob stopper - small piece of Swix CH8 is always in backpack, but I prefer to take care of my skins at home already. I guess that's same as Skin wax or?
Next to that, ski crampons, unless there's really only powder and I know for sure, there was no wind anywhere, two ski straps, if I move skis to backpack, and there's also crampons and ice axe or two, if tour requires climbing some steep faces. For food, I almost never use anything but home made powerbars. Sandwiches are not too tasty when cold, neither is chocolate, and with 3 or 4 home made powerbars, I'm good for 10h tour. Water is more of an issue for me then food.
Oh and I forgot... plastic strip and bag for skins. All my Pomoca skins have such glue, that you sprain your shoulder dragging them apart if you put glue to glue. Which on the end is not so bad thing, as even for sixth transition at -20c, glue still works
So no matter what, I prefer to stick that plastic sheet between skins when putting them to backpack.