I heard my father say it is unIslamic to sleep in one's underwear because being without clothes for too long is against etiquette, and is rude because people may walk in on you. I also read that it leads to angels not coming, and that a jinni possession may happen if you are naked without saying "Bismillah" first. I also heard that you shouldn't be talking while listening to Qur'an, that you should not be vengeful, that you should say "assalamualaikum" when entering a house because of angels there, and that the etiquettes of dua is that you should start with praising Allah and sending salam unto rasulullah (saws) and having a mindful heart, but I also heard you should do it AFTER the dua, as well as the basics, like saying salam to muslims, saying bismillah before everything, using right hand for eating, not gossiping, etc. which of these is true or nor true, and is there anything i am missing? what do you feel is an essential part of Islamic etiquette, such as core virtues, rules, etc. and what do you feel is neglected and or not talked about?