Vows and Conduct for Newly Ordained Monk
You asked whether there is a time when it is appropriate to wear sleeves, for example, when you go to Europe, to look more normal, or in cool weather. Generally, it is better not to wear sleeves. But if it's unbearably cold, then sometimes wear them.
Otherwise, try not to, OK? Otherwise, what happens is, you get habituated to wearing sleeves and wear them most of the time, even when there's no need.
So he chose those in order to tame and subdue the mind, have less delusion on the path to liberation and quickly achieving enlightenment, and to have a happy and generous mind. Therefore, you shouldn't follow other Sangha who are not following the Buddha's example.
At first, you have to abandon certain things in order to develop the mind. You have to see what is to be avoided and what is to be practiced.
Then, later, when the delusions are gone, then you go back to those things you had to abandon at the beginning.
It doesn't become dangerous for you.
At that time, you will have already practiced tantra, with the realization of guru devotion, seeing the Buddha as the guru, one guru as all buddhas, and one buddha as all gurus, and have a stable renunciation of samsara and attachment.
Before these later stages, your body/mind doesn't have control, and you have to abstain from the dangers. But your mind will develop and change.
So, to return to your question, you need to take the vows seriously.
Inspiration comes from that. Otherwise, it can make others degenerate the vinaya. You need to respect the abbot like Lord Buddha. According to the Hinayana, you don't see him as Buddha, but you respect him as Buddha, like a father.
The abbot should help and guide you like a son.
Regarding your question about sometimes having to eat after 12:00, if you have taken the eight Mahayana precepts, but you have a job or something, and you can't have lunch before 12:00, there's still benefit in keeping the vow, even if you have to eat after 12:00.
If you're not sure what time you’ll be able to eat, say “After lunch I won't eat.” Make the vow in that way.
Sometimes something happens and you have no choice over whether you can eat before 12:00 or not, for example, if you are traveling. This is not due to laziness or a mistake, but due to circumstances.
Try, if you have the freedom, to practice the fasting vow for one year. That doesn't mean after a year you never keep that vow, but at least keep it purely for some time, so in your life there's a certain period where you kept it purely. The general idea is to keep it as much as one can.
Sometimes I tell Sangha, if you are settled in one place, then try to fast. It's not just for you, but for other sentient beings, to free them from the cause—delusions and karma—and bring them to enlightenment.