Very good conversation starter. You've given a good "definition" of self preservation, but we probably need to specifically state what we mean by "a virtue" or "a virtue in Epicurean philosophy" too. Because we have the overarching principle that pleasure is the guide to everything, so nothing can be virtuous if it does not promote pleasure (which I think we can consider to include within "promoting pleasure" the subset of activities included in "avoiding pain").
So keeping in mind that the goal is always pleasure, we can't say that self-preservation is ALWAYS what the Epicurean will pursue (which is probably a way to consider a "virtue"?) because we know that Epicurus said that on occasion one will die for a friend, and there is the reference in Torquatus that we will sometime choose to leave the theatre when the play ceases to please us.
But there are the references that say "life is desirable" (Menoeceus) and also the statement that the man is of little account who has many reasons to end his life (I always forget the cite for that. Anyone?) And there is the PD to the effect that preservation of one's safety from others is a natural good.
So in GENERAL self-preservation would be the chosen course, but just like everything else other than "pleasure" itself, there are definitely going to be exceptions.
How's that for a start?