The Techum Of Yaakov

The midrash on the possuk (33:18) וַיִּ֖חַן אֶת־פְּנֵ֥י הָעִֽיר  says that Yaakov came to the city right before Shabbos and set up his location so that he wouldn't have a problem of leaving the techum on Shabbos.  Rav Yosef Engel (בית האוצר ח"א כלל כ') discusses why is it Yaakov who sets up the techum of Shabbos and not Avrohom.  However, in derush we understood that techum represents boundaries (see Meshech Chachma.)  The other Avos weren't challenged to separate themselves from the rest of the world, their actions made them unique and separate from everyone.  Yaakov on the other hand was challenged by his brother, Esav.  Esav wasn't unceremoniously thrown out of the family like Yishmoel, he remained the brother of Yaakov.  Specifically because of this, it was imperative for Yaakov to set up boundaries.  His family had to know that we aren't in any way related (in terms of outlook in life) with Esav.  It is well known the idea of the Beis Halevi that Yaakov prayed "save me from my brother, Esav" it is sometimes that brotherly feeling that is the greatest harm.  The Gemorah in Chullin 91a has an opinion that the angel of Esav came to Yaakov in the form of a talmud chacham.  The Avnei Nezer explains that sometimes the yetzer harah tries to convince us to do something through an entire shiur klali about why it’s right.  The only way to protect against that is to have fixed boundaries so that it is intuitive that those lines won't be crossed.  The midrash derives from the language of the possuk (34:26) ויקחו את דינה, not ויצא דינה that the brothers had to drag Dina out of Shechem.  How could it be that Dina who was coerced by Shechem wouldn't want to leave?  We see the dangers of coming too close to those that are antithetical to Jewish beliefs.  They are very incising and when one gets sucked in it's hard to come out.  That is why it's of utmost importance to not become attached and accepting of evil outside views and influences (see Rav Yeruchem.)
I never understood while in yeshiva the importance of adopting the distinct look of a penguin.  Why must we emulate those birds of the Southern hemisphere?  But I subsequently understood that it is when one who (c"v) isn't found within the walls of the Beis midrash, when he is wondering around the many Esav's of the world, that it is important to have those boundaries as a reminder that Esav may be a kin brother, but not a brother in heart.