pilgrim wrote:What makes one a Theravadin? Do I have to unequivocally accept all 3 baskets
A Theravāda practitioner dismissing the Theravāda Abhidhammapiṭaka and Theravāda Khuddakanikāya texts such as the Paṭisambhidāmagga is analogous to a Chan/Zen practitioner dismissing the Platform Treatise of the Sixth Patriarch or a Nyingma practitioner dismissing the Guhyagarbha Tantra. In each of these cases these texts form the doctrinal basis for practice and textual interpretation within each school.
Thus, if one fails to accept the canonical doctrines and path structure as presented in the Abhidhammapiṭaka and Paṭisambhidāmagga, then one isn't really engaged in Theravāda practice. This doesn't mean that every practitioner has to be an Abhidhamma scholar, just as not every Nyingmapa practitioner has to be a scholar of the Nyingma Canon. But it makes little sense for a Theravāda practitioner to dismiss well over a third of the Theravāda Canon, especially since it is this large section of materials which are unique to the Theravāda.
It's also worth mentioning that the Theravāda Abhidhammapiṭaka actually accords with the sutta strata of teachings nicely. In general, it is more conservative and therefore closer to the suttas than is the case for the extant Sthavira Sarvāstivāda treatises, etc.
If we approach the Abhidhammapiṭaka as a prescriptive and descriptive aid to help clarify practice and textual interpretation of suttas, and not
as a closed system of ultimate truth which marginalizes the suttas as being of lesser importance, then this combination of canonical Vinayapiṭaka, Suttapiṭaka, and Abhidhammapiṭaka offers us a very workable and valuable set of teachings to guide our practice.
pilgrim wrote:everything in the Commentaries, the Visuddhimagga
The commentaries and the Visuddhimagga are not canonical. Moreover, the commentaries do not present a homogeneous doctrine. It's not uncommon to find multiple opinions presented regarding a particular canonical passage, etc. It's also not uncommon to find quite dubious etymologies of particular terms and an obvious lack of understanding of canonical metaphors, and so on. This is due to the commentaries being authored by people separated from the historical, geographical, and cultural situation of the early Buddhist community. This has been well documented by a number of translators and scholars. Therefore, while the commentaries are also important, they aren't of the same caliber as the Tipiṭaka.
All the best,