See the Talmud’s elaboration on 49b:
על מנת שאני עשיר אין אומרים כרבי אלעזר בן חרסום וכרבי אלעזר בן עזריה אלא כל שבני עירו מכבדים אותו מפני עושרו
‘On condition that I am wealthy,’ we do not say, like R. Eleazar b. Harsom and R. Eleazar b. Azariah, but as long as he is honoured by his fellow citizens on account of his wealth.
Yamaka or Yarmulke is actually a contraction of Yareh MiKah - יָרֵא מִקָה - i.e. to fear Gcd, the purpose of covering one's head, originally.
Say Yareh MiKah a few times in succession and it will start sounding like Yamaka or Yarmulke. For some reason, Yarmulke became the "official" way to say it. Compare to the etymology of Goodbye - from godbwye (1570s), ...
The opinion of the Aruch Hashulchan (EH 38:94) regarding this matter is that rich is a fluctuating term which is determined per the locale.
וזהו ידוע שבעיר קטנה נקרא עשיר בסכום קטן ובעיר גדולה לא נקרא עשיר בסכום כזה, ולכן תלוי לפי המקום שהוא דר בו [נ"ל]
It is commonly known that in a small city it takes less wealth to be considered rich than in a big ...
Your answer is within the sources in your question.
Torf means an exposed place, that should be covered.
מקום התורף - woman's genitalia should be covered if exposed.
Document's תורף - Are the exposed blanks, that should be covered (by writing) [Also, leaving those blanks open make the document dangerous sometimes].
תורפה של ירושלים - Jerusalem's ...