It is very clear that the good is pleasure and vice versa, but it is not at all clear waht pleasure(s) actually determine a blessed life. Only the absence of pain does that; but he expects that lots of other pleasures will be present in a blessed life.
As to what plesaures actually determine a blessed life, I think I recall Gosling & Taylor examining that at length in "The Greeks On Pleasure" in their chapter on the katastematic/kinetic issue, and concluding that there is nothing mysterious at all about these pleasures, as they include all the normal and ordinary pleasures of regular human life.
As to how "absence of pain" plays into that, it clearly can't mean "total absence of pain in every aspect of life," if we are to accept (as we should) that Epicurus considered himself to be happy even during his last days of extreme physical pain. On the other hand, if "absence of pain" simply means "pleasure" as Torquatus insists to Cicero repeatedly that it does, then there's no issue, as Epicurus tells us that his mental pleasures from friends and philosophy outweighed the physical pains.
On Ends Book Two, 9 : Cicero: “…[B]ut unless you are extraordinarily obstinate you are bound to admit that 'freedom from pain' does not mean the same thing as 'pleasure.'” Torquatus: “Well but on this point you will find me obstinate, for it is as true as any proposition can be.”