Are all those quoted passages from the minor rules? That is, those rules that the Buddha said the monks were allowed to change when he passed away?
“After my death, Ananda, if the Sangha is willing, the lesser and minor rules may be abolished.”
- Dīgha Nikāya 16, Mahāparinibbāna Sutta
Yes, those quotes are in lesser and minor rules. The Buddha’s allowance is not to “change” but to “abolish”, and this allowance is the most used justification by the flaccid monks who don’t follow most of the Vinaya. However, it’s not new, and happened while the Buddha was alive.
Then the group of six bhikkhus considered: “At present, many bhikkhus, elders and newly ordained and those of middle standing are mastering Vinaya under the Ven. Upāli. If these become properly versed in Vinaya they will win us to [them], they will win us rounds how they like, when they like, for as long as they like. Come, your reverences, let us disparage Vinaya.” Then the group of six bhikkhus, having approached the bhikkhus, said: “On account of what are these lesser and minor rules of training recited? They only tend to remorse, to vexation, to perplexity.” Upon hearing this The Buddha, rebuked them: “How can you, foolish men, disparage Vinaya? Foolish men, it is not for the pleasing of non-believers nor believers, it is to the detriment of both, and it causes wavering in some.”
“Should any bhikkhus, when the Pātimokkhas being recited, say: 'Why are these lesser and minor training rules recited when they lead only to anxiety, bother, and confusion?' For criticising the training rules, there is an offence of expiation.”
- Pācittiya Pāḷi, Pācittiya 72
“Bhikkhus, I want to go into solitary retreat for three months. I am not be approached by anyone except the one who brings the food.” Then, an agreement was made by the bhikkhus at Sāvatthi, saying: “Whoever approaches The Buddha in these three months should be confess an offence of expiation.”
Then the Ven. Upasena approached The Buddha together with his followers. After The Buddha exchanged friendly greetings with them, asked: “Do you know, Upasena, of the bhikkhu’s agreement at Sāvatthi?” Ven. Upasena replied in negative, and after hearing it from The Buddha, said: “Venerable sir, the bhikkhus at Sāvatthi will be well-known for its own agreement, we will not lay down new rules or abolish any old rules.” “That is very good, Upasena, what has not been laid down should not be laid down, nor should abolish what has been laid down, but should dwell in conformity with and according to the rules of Vinaya which have been laid down.”
- Pārājika Pāḷi, Nissaggiya 15
Also, it's important to remember that even at the first council those Arahants didn’t abolish any rule.
Ven. Ānanda informed the elder bhikkhus that The Buddha, at the time of his attaining Nirvana said to him: “After my death, if the Sangha is willing, the lesser and minor rules may be abolished.” But Ven. Ānanda never asked The Buddha which are the lesser and minor rules. Thus, five hundred elder bhikkhus of the first council were not unanimous being on variant interpretations regarding the lesser and minor rules.
Then the Ven. Mahā Kassapa informed the bhikkhus: “Venerable sirs, there are rules for us which affect householders, and householders know concerning us: 'This is certainly allowable for the bhikkhus, this is certainly not allowable.' If we were to abolish the rules there would be those who would say: 'Rules had been laid down by The Buddha only until the smoke of his funeral pyre lasts; while The Buddha was amongst them these followed the rules, but since The Buddha has attained final Nirvana, they do not follow.' If it seems right to the Sangha, what has not been laid down should not lay down by the Sangha, nor should it abolish what has been laid down, but should dwell in conformity with and according to the rules of Vinaya which have been laid down.”
- Cūḷavagga Pāḷi, Pañcasatika Khandhaka
My take on abolishing the rules is this. The Buddha laid down Vinaya for ten reasons:
1. The well-being of the Sangha.
2. The comfort of the Sangha.
3. The restraint of bad-minded persons.
4. The comfortable living of virtuous bhikkhus.
5. The restraining of defilements pertaining to this life.
6. The warding off of defilements pertaining to the next life.
7. The inspiration of those without faith.
8. The increase of those with faith.
9. The long lasting of the True Dhamma.
10. The support of the Vinaya.
If thinking of not following a rule, then best to investigate own mind for the root of that intention (yoniso-manasikāra
). As in the Vajjiputta Sutta (Aṅguttara Nikāya 3.83) http://www.accesstoinsight.org/tipitaka ... .than.html
, see whether the intention is directed at abandoning of passion, aversion, and delusion or not. A monk I know suffered a lot by a tumor due to his unwillingness for a surgery near his genitals. However, later he pondered on this prohibition in Vinaya and decided to go through the surgery as it will help him to meditate better as a healthy person. In this case, he was neither lax in Vinaya nor disrespecting it.