Here are some quick items on Nedarim 76-81:
Why wouldn’t we use a Kal vaChomer for this? Because Kal vaChomer is the only method of derashah (hermeneutical principle, for the multisyllabically inclined) which one may employ on his own say-so and personal logic, and is therefore considered vulnerable to error. For the same reason, we say אין עונשין מן הדין, a court may not punish based on kal vachomer deduction.
Regarding the word “Yom” you must see Rashbam on Bereishis 1:4 (ויהי ערב ויהי בקר), and Ibn Ezra on Shemos 35:5 (ביום השבת). (Note that Ibn Ezra wrote an entire screed against Rashbam’s philosophy of Yom - it's the Iggeret haShabbat, available on-line here.)
Rav’s use of “chavivi” “my beloved” for his uncle R’ Chiyya is parallel to our own use of דוד for uncle. Note that R’ Chiyya was his maternal and paternal uncle; see the beginning of Pesachim, 4b or so.
The Ran and the Rosh have entirely different explanations of what R’ Chiyya bar Rav and Rabbah bar Rav Huna were doing.
It is interesting to note the Rosh’s explanation of R’ Chiyya bar Rav’s actions vis-à-vis his wife’s nedarim, given the history of R’ Chiyya with his father (Rav)’s wife, who used to intentionally do the opposite of what his father wanted, on Yevamos 63.
See the Rosh’s two approaches in או דילמא
See the Ran’s citation of, and disagreement with, the Rashba.
The Ran specifies that one may only do שאילה upon his upholding of a neder on the same day.
Based on the top of 81b, it appears that all of the “I will not bathe” references here are to bathing in the genital area, specifically.
Halfway down, חייל עליה נדרה should be חייל עלה נדרה, I think. I haven't checked the usual sources for this, though.
The Ran and pseudo-Rashi offer different explanations of the term הנאת רחיצה
Rav Moshe Feinstein in Yoreh Deah 1:145 notes that in R’ Yosi’s case of “our laundry vs. their lives,” it doesn’t actually refer to a life-and-death situation.
Shemuel, once again, weighs in with a medical opinion.
Re: Sha’amumita, see the Depression issue raised under שעמום in Kesuvos 59b.
See, of course, the famous Rabbeinu Yonah cited by the Ran on the problem of not reciting Birchot haTorah before learning Torah.
The fox analogy is an attempt to use clean language.