1) Rashi comments on Yaakov's request אַל נָא תִקְבְּרֵנִי בְּמִצְרָיִם that there are three reasons why Yaakov did not want to be buried in Egypt:
סופן להיות עפרם כנים, ושאין מתי חוצה לארץ חיין אלא בצער גילגול מחילות, ושלא יעשוני מצרים עבודה זרה.
I saw quoted in the name of R' Shimon Moshe Diskin, R"Y of Kol Torah, that the reason of סופן להיות עפרם כנים is not just because משום צער המת (see Gur Aryeh) and would not be a very nice thing, but it is based on a din. The gemara (Sanhedrin 46b) learns that burial must be done in soil. When the plague of kinim came, all of the soil of Egypt turned to lice. The Midrash (Shmos Rabbah 10:7) writes לְפִיכָךְ נֶהְפַּךְ עֲפָרָם לְכִנִּים וְחוֹפְרִין אַמָּה עַל אַמָּה וְלֹא הָיָה שָׁם עָפָר, שֶׁנֶּאֱמַר: כָּל עֲפַר הָאָרֶץ הָיָה כִנִּים, that even down to the depth of an amah there was only kinim. If so, had Yaakov been buried in Egypt the mitzvah of kevurah would be bateil, as he would no longer be buried in earth. Therefore, he asked to be carried to Eretz Yisrael.
It's a brilliant chap, but I have one small question, or maybe it would be better to call it an observation. The Kli Chemdah points out what seems to be a stirah in Ramban. Ramban comments in parshas Chayei Sarah on the pasuk אִם יֵשׁ אֶת נַפְשְׁכֶם לִקְבֹּר אֶת מֵתִי מִלְּפָנַי that מלפני – כי אם לא תעשו כן, אקברנו בארון Avraham told the Bnei Chais that if they won't sell him a burial plot, he will bury Sarah in an aron and leave her in a coffin. However, Ramban in Torah haAdam writes that the mitzvah of kevurah m'doraysa can only be fulfilled through burial in soil. How then could Avraham have left Sarah in an aron? What about the mitzvah of kevurah? Kli Chemdah answers that the reason behind buying the body in soil is based on the din of hashavas ha'gezeilah. Man is created from dust of the earth. Either he can fulfill his mission and be metakein that dust and elevate it to something holy, or the dust must be returned to its source. (Nafka mina to this hesber: gezel is prohibited even to a ben noach, so they too have to bury their dead.) Sarah achieved the goal of sanctifying the dust her body was created from, so she did not need to be returned to the soil. For her, burial in an aron would have been sufficient. The same is true, says the Kli Chemdah, of Moshe, as no one knows where the burial place of his body is. The same is true of Yosef, who was placed in an aron after death and according to some views that aron was sunk into the Nile, not buried in land. Given all of the above, I don't think it would be a stretch to say the same is true of Yaakov Avinu. So what if the soil would turn to kinim and he would not have burial in soil? His body was elevated to a state of holiness and did not need to return to the earth?
Worth noting as well that the Sifsei Chachamim asks why Rashi quotes three reasons for Yaakov's request -- wouldn't one justification be enough? He comments: ״ל דצריך לג׳ טעמים הללו דאי משום כנים לחוד היה לו לצוות לעשות ארון מברזל לכך פירש גלגול מחילות etc. I don't know what the S.C. does with the gemara in Sanhedrin, as לעשות ארון מברזל is not an option if you hold you need burial in land.
Again, this is not a question, as it is all predicated on the Kli Chemdah. You can find some other way to answer up that Ramban and avoid the whole issue. Just thought it was worth pointing out.
2) Yaakov blessed Yissachar (49:15) וַיַּרְא מְנֻחָה כִּי טוֹב וְאֶת הָאָרֶץ כִּי נָעֵמָה וַיֵּט שִׁכְמוֹ לִסְבֹּל וַיְהִי לְמַס עֹבֵד. A question we've dealt with before: the bracha seems self-contradictory, a stirah minei u'bei. If Yissachar loved menucha, then what is the meaning of וַיֵּט שִׁכְמוֹ לִסְבֹּל, that he accepted a burden on his shoulders? There is no menucha in that!
Seforno writes that the מְנֻחָה referred to here is המנוחה בשלמות המושכלות, achieving spiritual perfection. Midrash Rabbah: וַיַּרְא מְנֻחָה כִּי טוֹב – זוֹ הַתּוֹרָה, שֶׁנֶּאֱמַר (משלי ד׳:ב׳): כִּי לֶקַח טוֹב נָתַתִּי לָכֶם. Menucha does not mean that Yissachar loved indolence or was lazy. What it means is that in comparison to the lot of Zevulun, who went out to do business and fight wars, Yissachar preferred to toil closer to home, to expend his energy toiling under the yoke of Torah.
Maharam Shick explains the lesson of this pasuk in a way that probably runs counter to everything modern chinuch is all about. A bit of intro from the Shem m'Shmuel to set the table: the gemara (Brachos 13b) writes
אמר לי' רב לר' חייא לא חזינא לי' לרבי דמקבל עלי' מלכות שמים, אמר לי' בר פחתי בשעה שמעביר ידיו על פניו
Rav remrked to R' Chiya that he was perplexed because he never saw Rebbi accept upon himself עול מלכות שׁמים. Rav Chiya responded that Rebbi did so when he covered his eyes in the shiur, like we cover our eyes when we say shema. The Shem m'Shmuel in parshas VaEschanan explains Rav's bewilderment:
ופרשנו דשאלת רב היתה דהיות רבי שהי' כל ימיו בדביקות עצומה איך שייך אצלו קבלת מלכות שמים שאצלו איננו עול אלא אהבה רבה [ויש להוסיף ולומר היות רבי מזרעא דדוד קאתי שהיתה מדתו השתוקקת עצומה ואהבה רבה לאלקות כמ"ש (תהלים ס"ג ב') צמאה לך נפשי כמה לך בשרי וכל ספר תהלים מלא מזה, וכן היתה בודאי מדתו של רבי, ואמר על עצמו שלא נהנה מעוה"ז אפי' כאצבע קטנה, ולעומת שלא נהנה מעוה"ז היו כל תענוגותיו רק אלקות כמו שבא ברמז בדבר אמלאה החרבה אם מלאה זו חרבה זו כמו שהארכנו בזה במק"א, איך יתכן שנקרא אצלו עול]
What bothered Rav is that for someone as connected to ruchniyus as Rebbi, is there really such a thing as עול מלכות שׁמים, as the YOKE of heaven? Yoke means it's a burden, something you have to work hard at. If someone gave you the job of eating chocolate ice cream or your favorite cake, you wouldn't call that a yoke, you would call it a pleasure! For Rebbi, serving Hashem was chocolate ice cream. Where's the burden?
Whatever the answer is (look up the Shem m'Shmuel), you see from Rav's question that there is a tremendous maa'lah to serving Hashem not because doing so is like chocolate ice cream, but because it is קבּלת עול, because it is a necessity even if we wouldn't enjoy it.
וַיַּרְא מְנֻחָה כִּי טוֹב, Yissachar saw that המנוחה בשלמות המושכלות is the ultimate good besides which nothing can compare or complete. It was better than riches, better than chocolate ice cream. Nonetheless, וַיֵּט שִׁכְמוֹ לִסְבֹּל His motivation in avodas Hashem was not just because Torah is enjoyable, but rather he accepted what he had to do as an עול, as service, as something that must be done irrespective or whether it was pleasurable or not.
Today when kids go to school every morah and rebbi wants them to feel "geshmack," not just in first and second grade, but even in high school and beis medrash. I don't know what people raised in that way do when learning does not feel so geshmack, as is the case many times after a long day of work or when dealing with other difficulties. We all hope and pray that וַיַּרְא מְנֻחָה כִּי טוֹב, that we should love learning and experience the joy and pleasure in Torah and mitzvos, but we also need the motivation of וַיֵּט שִׁכְמוֹ לִסְבֹּל, to keep going even when the going is tough.