Rav Ahron Felder zt"l was a talmid muvhak and spent many years serving Rav Moshe Feinstein. Among the seforim he authored is the multi-volume Rishumei Aaron, which contains rulings and halachic opinions from Rav Moshe that are not found anywhere else.
In Volume II O"C Siman 8 He states that Reb Moshe held there is no obligation to wear ones tzitis ...
A complete answer is well beyond me, but let me just state one of the basic rules:
Even if Bitcoin is considered a currency, at this point in time it would only be considered a foreign currency, since most people would not accept it as payment.
When lending a foreign currency, it is the same as lending a commodity like gold or flour, and at commercial ...
The understanding behind this teaching from Pirkei Avos 1:6 is more to demonstrate the need for fixing for yourself a mentor and guide, so that you can learn and grow from. Unlike a friend which you should 'acquire', here the advice is to take pains to formally 'make' for yourself a Rav as this is a necessary requirement for self growth.
Rabbeinu Yonah ...
The very first verse in the Book of Psalms says:
אַ֥שְֽׁרֵי הָאִ֗ישׁ אֲשֶׁ֤ר ׀ לֹ֥א הָלַךְ֮ בַּעֲצַ֢ת רְשָׁ֫עִ֥ים וּבְדֶ֣רֶךְ חַ֭טָּאִים לֹ֥א עָמָ֑ד וּבְמוֹשַׁ֥ב לֵ֝צִ֗ים לֹ֣א יָשָֽׁב׃
-- Happy is the man who has not followed the counsel of the wicked, or taken the path of sinners, or joined the company of the insolent. [Psalms 1:1]
In commenting on it, ...
R' Moshe Feinstein says that it's pashut that at a time when it's hard for her she is not obligated. I'm not sure what he means by "hard for her" though. Ask your LOR.
By the way everyone must have a Rav who they feel comfortable asking these questions to.
You can daven drunk until you slur your words:
If one drank to the point that he is unable to speak in front of a king without slurring his words, then it is forbidden for him to Daven Shemoneh Esrei until he becomes sober.
Footnote 9 describes 2 states that are forbidden to daven-
There are two levels of cannot speak properly ...