I've been thinking about this topic for a while and have been waiting for a thread to pop up.
First off I completely agree that religious rights are held above most other types. I religious person can ask for a meal that does not have pork (or whatever other animal product), but unless you claim you're vegetarian or something, it doesn't matter if you don't like pork, that's all you're getting.
I don't have a problem with making accommodations for most beliefs, if you don't want to eat pigs, fine by me, but there's no reason I should have to.
I assume they view a non-Jewish inmate asking for kosher food (which is also more expensive) as a sort of 'non-essential' request similar to asking for an X-Box or something. The question then might become, I suppose, 'why is the religious view of the Jewish inmate held to a higher regard than the preference of the non-Jewish inmate?' To which I say, depriving the Jewish inmate would, if he were sincere, cause a degree of mental and emotional anguish, not present in the other inmate who just wouldn't be getting his way.
Who the fuck cares if it causes slightly less emotional anguish, let the non-Jewish guy get a Kosher meal. You're feeding him anyway, why piss him off? There's no problem with letting people have extra choices, whatever you believe doesn't harm me, for the most part (Once you get Evangelical Christians in Government though, they tend to fuck a lot of shit up).
Giving everyone a variety of reasonable choices would suffice for any of the main religions and it completely removes the element of partiality. It also means that once someone comes up with a ridiculous set of customs, they would not get accommodated.
Given the meal idea:
A Christian may be able to eat anything.
A Jew may want a kosher meal.
A Muslim may want a meal without pork.
A Vegan may want a meal without any meat.
A Bad_Ass may want a meal made entirely of salted bacon.
If there's a Main Dish, Kosher Dish, No-Pork Dish, and Vegan Dish, EVERYONE should be able to chose ANY of the above. I don't see how there should be any complains with this (except for Bad Ass, he gets screwed =/). There could be possibly 3 options at once, where at least one of above cultures is satisfied with at least one.
As for holidays, there's a bunch of shit ones both in the States and Canada. We have 2 that I'm not sure even have names. I'm sure it'd be feasible to change it to a Muslim/Jewish holiday if they were at all regular. (Easter Weekend is fucking annoying as is.)