Avi K,
What happens when chumrot conflict? For example, in your hospital case those who are makpid to eat gebruchts as per the Gra, who said that those who do not will ahve to give an account as to why they did not do the mitzva of simchat Yom Tov, lose out (BTW, someone I know said that he has a cousin in America who is such a big Mitnagged that he eats it every day EXCEPT the eighth).
I don’t think that someone who is unable to eat gebrochts because s/he is in the hospital and the kosher kitchen there does not have them will have to give an account. Also, the hospital kitchen not having gebrochts does not stop the patient/guests from bringing their own to the hospital, if they are makpid to eat them.
What about those members of the Eidot HaMizrach for who it is not Pesach if there is no rice?
See above.
If, G-d forbid, I were in the hospital over Pesach, I would be grateful if I had matza, marror, wine, and anything else kosher to eat, and the ability to eat it.