That is an interesting suggestion Michele!
I think it does have some potential, at least for certain uses.
However as to this:
it does not have a symbol with which it can be identified around the world.
.... I am not sure that the ancient Epicureans would agree --- it seems as if they did have something they used: the bust of Epicurus himself, which you are holding in your excellent avatar! ![]()
This is an interesting questions from many perspectives. It probably also relates to the use of the term "Epicurean" as the name of the philosophy rather than "hedonism" or even "atomism" or the like. Both words have uses, but neither word captures the whole philosophy like identifying it with the founder himself does.
And I think that relates too to the issue that Don refers to, such as the use of the Greek letter (such as Society of Epicurus does) representing "friendship". Anything that conveys only one aspect of the philosophy fails to capture the fullness of it, and may tend to falsely imply that one aspect of it is "the most important."
I know personally that was my immediate reaction to the letter indicating friendship, and I think that's also why I rarely refer to the philosophy as atomism or hedonism. Both words have their uses, just as this suggested symbol might.
I suspect even the christians ought to be concerned about the cross for the very same reasons. (Which is one reason I gather than the Mormons do not use the cross very often, even though they consider themselves to be christians.)
If the question were: What unicode symbol on a keyboard would work best, I doubt anyone could come up with any better.... though it would be interesting to consider the options and think about that.