Actually, the view of having no self is considered to be just as incorrect as the view of having a self. (But this doesn't have anything to do with Dr Flower's book)For LHP moreso Theravada's experimental innovations I think.
In Theravada there is no "individual" much less "coming" or "going" anywhere. Core difference between Theravada and Mahayana is that Theravada rejects any essential Self. Mahayana sneaks in the notion of Buddha-nature or primordial Mind underneath experience in contrast. So in a sense if a philosophy centers on an essential Self, Theravada would be more unfamiliar. Theravada is also almost exclusively renunciate. Mahayanists can achieve enlightenment without monasticism, and Tantra is even less renunciate -- focusing on using everyday sensory world, emotions, and non-monastic religious teachers.
Not sure if Pali Canon is older. It probably is, but it can also be debatable. You're right; Theravada is more "scientific," but that was an outcome of foreign influence. The incentive to use only the Pali Canon, read it as an instruction manual, and recreate from it Buddha's meditation techniques as central to the Buddhist path arose in dialogue with the 19th/20th century West (by way of Protestantism; same 'sanitization' happened with yogic religion in India). For a talk on this see "Is Mindfulness Buddhist? And Why it Matters.", and "Theravada Reinvents Meditation".
The following post link is in reference to a Pali text.
The suttas don't negate atman.... | Page 2 | ReligiousForums.com