Re: what is the definition of Ahl ul Bayt
ma maooli who is a syed today is a loaded question. Few can trace their linage to the Prophet and if u think zakat is haram on you then by all means believe in that.
Regarding sources its a more complicated situation that what u have painted ( and u shud know this considering you are professionally qualifed to comment on this).
If 12er aqeedah was so crytal clear if would go through so many stages before it was finally formalized.