Camotero something else going on here that I think is relevant, and I see myself making this point a lot lately:
It may look like we (I? Epicurus?) are taking things to unnecessary extremes by carrying things out to "extreme" logical conclusions, but I think that is exactly what Epicurus was doing. Epicurus was faced with teaching philosophy in ancient Athens, where everyone who was anyone was expected to know and understand the arguments of Plato and other similar authorities, starting with Philebus on pleasure but also lots of other dialogues with similar arguments. Those guys in Athens were fully committed to "logic" as the key to everything, so Epicurus could ill afford to take half-measures and appeal to practicality like we might do today. I think that is one reason that some of us have problems coming to grips with how extreme some of the conclusions can sound, but after going through Philebus and other Platonic dialogues a couple of times I am convinced that Epicurus thought that if he left any logical conclusion unanswered then his entire system would be ridiculed into obscurity.
Yes we are appealing to the sensations and feelings as the ultimate guide of how to live, but we are doing so only after a rigorously logical argument as to why we are doing so. Anything less than than would be pure assertion on our part, and make our philosophy arbitrary, as a result of which it would rightly be laughed out of Athens.