Huifeng wrote: However, in the 小小戒可捨 "the minor precepts may be rescinded" case, as well as this, they refer to a minor issues of decorum (perhaps the siksapadani) and cultural issues (eg. bathing times). While I don't recall if it has been raised in this thread, such alterations seem hardly to extend to issues such as how the ordination process takes place, the precepts of "defeat" (parajika), and other more core issues.
The definition of "minor precepts" differs according to the school as you know. Nevertheless, the Buddha is on record saying the sangha could abandon minor precepts and change things accordingly. Naturally as a śramaṇa that wouldn't entail abandoning precepts against sex and theft, but nevertheless modifications could be made. That says to me that the Buddha was fine with changing the system as needed.
In fact modifications were made and hence the Vinaya literature differs from school to school (there's even apparent Mahāyāna adaptations to be seen in some places). The core essentials are still largely identical, but then the original Japanese monastic systems not based on the Vinaya are not so different either. Things changed and now priests get married and so on, but before it was a respectable system that worked and plenty of monastics had long careers full of practice and fulfilment without having to defer to Vinaya texts.
In any case, life is short and we're all going to die sooner or later. Having rules for organizations is necessary, but acting like Pharisees and clinging to rules and procedures as if they're god-given commandments that are prerequisites for liberation is not going to help anyone. It should be an organic process, which I believe was the Buddha's intent. The Japanese managed fine without all the Vinaya procedures for many centuries. They had rules and procedures, but these were adapted to and organic to their environment. That should be commended and emulated where necessary.