Again, you are confusing Tzorech Shabbos, which you correctly quote MB325:62 as “somewhat difficult to do without” with Tzorech Gadol.
As I said earlier, there are (at least) two levels of tzorech gadol; Health’s case was one of not having cholent, which would be the lower one which is called tzorech or kavod Shabbos, and subject to all of the dinim in 253, 325, and 328.
Again, R’ Moshe seems to feel that even important Shabbos foods reach the criteria of “tzorech gadol”; he says that if the “ikar ma’achalei Shabbos” are in a refrigerator, one can ask a nochri to remove the bulb so that the Yid can later get the food. It’s possible to learn that R’ Moshe’s tzorech gadol is that he’s afraid that a Yid will open the fridge, turning on the light, and be oiver on havarah d’oraiso if the nochri doesn’t remove the bulb, and that this concern is only if the main foods are there, but this is not the pashtus in this teshuva.
“I don’t think one would be required to protest if someone had the R’ma to rely on”
See the Aruch HaShulchan I quoted above that you must.
One can rely on R’ Moshe not to protest.
Unless it was k’Ma’achal ben Drusai before Shabbos, which is most likely the case.
Health intimated earlier that it was raw.
That being the case, besides for the issurim of amira l’aku”m and bishul aku”m, I think there’s a third issur of muktzeh (unless in your 150 pages of mareh m’komos on muktzeh someone holds that if you thought food was cooked, it’s not muktzeh even though it was actually raw). Only the meat might not be a problem (I think some contemporary poskim hold raw meat is muktzeh because it’s no longer common to eat raw meat).