Coffee,
I would like to ask you a question (according to Rashi et al in the plain and pashut sense)
We say תורה צוה לנו משה מורשה קהילת יעקב the word מורשה (according what I heard at least) is that it means inheritance (and because we say קהילת יעקב it’s understood from יעקב) how can an alive person give over an inheritance, inheritance is only done after death?
Additionally
Doesn’t it say Hashem doesn’t affix His name to a person while he’s alive? (Hashem said to Moshe “אלקי אביך” and the midrash says that’s how Moshe knew he passed away) yet Hashem says אלקי יעקב
Excellent questions on Rashi and the other meforshim!
I suggest you look into it, find some nice answers, and maybe use this as a Dvar Torah or pilpul that you can deliver for parshas Vayechi.
It is obviously unnecessary to point out that even if we have unanswered questions on a true talmid chacham (like Rashi et al), that doesn’t ch”v invalidate their pshat.
However, I’ll give some thoughts that may answer your questions:
THOUGHTS TO ANSWER YOUR FIRST QUESTION:
1. The idea of מורשה is mainly emphasizing the WAY that Yidden received Torah: Just as a yerusha is passed automatically to all the children, even a little baby, so to Torah belongs to every Jew just because he/she is Jewish (as the Rambam writes: כֶּתֶר תּוֹרָה הֲרֵי מֻנָּח וְעוֹמֵד וּמוּכָן לְכָל יִשְׂרָאֵל. שֶׁנֶּאֱמַר (“תּוֹרָה צִוָּה לָנוּ משֶׁה מוֹרָשָׁה קְהִלַּת יַעֲקֹב”. כָּל מִי שֶׁיִּרְצֶה יָבוֹא וְיִטּל.
This doesn’t necessarily mean that we are getting Torah from a dead person. On the contrary, we are inheriting Torah FROM HASHEM.
2. קהלת יעקב does not necessarily imply an inheritance from Yaakov, for the Jewish people are called בני ישראל\כלל ישראל\בני יעקב\קהלת יעקב all the time, not necessarily referring to something that they have received from Yaakov himself.
Actually, the Ramban writes that מורשה קהלת יעקב means that Yaakov himself RECEIVES the inheritance as well:
וְדָרְשׁוּ רַבּוֹתֵינוּ (מדרש תהלים א), שֶׁלֹּא אָמַר מוֹרָשָׁה בֵּית יַעֲקֹב אוֹ זֶרַע יַעֲקֹב וְאָמַר קְהִלַּת יַעֲקֹב, לְרַמֵּז שֶׁיִּקָּהֲלוּ רַבִּים עֲלֵיהֶם וְתִהְיֶה הַתּוֹרָה לְעוֹלָם מוֹרָשָׁה לְיַעֲקֹב וּלְכָל הַנִּקְהָלִים עָלָיו, הֵם הַגֵּרִים הַנִּלְוִים עַל ה’ לְשָׁרְתוֹ וְנִסְפְּחוּ עַל בֵּית יַעֲקֹב, וְנִקְרְאוּ כֻּלָּם קְהִלָּתוֹ.
“Torah will always be an inheritance FOR YAAKOV and all those who gather around him.”
3. The Gemara (Sanhedrin 91b) states that the inheritance of Torah was since ששת ימי בראשית, way before the birth – and certainly death – of Yaakov:
תורה צוה לנו משה מורשה קהילת יעקב מורשה היא לכל ישראל מששת ימי בראשית.
These are just some points I thought of right away.
תן לחכם ויחכם עוד.
—
A THOUGHT TO ANSWER YOUR SECOND QUESTION:
Hashem said אלקי יצחק during Yitzchak’s lifetime. Rashi asks (בראשית כח, יג), how can this be, לֹּא מָצִינוּ בַּמִּקְרָא שֶׁיִּחֵד הַקָּבָּ”ה שְׁמוֹ עַל הַצַּדִּיקִים בְּחַיֵּיהֶם לִכְתֹּב אֱלֹהֵי פְּלוֹנִי?
Rashi answers: כָּאן יִחֵד שְׁמוֹ עַל יִצְחָק, לְפִי שֶׁכָּהוּ עֵינָיו וְכָלוּא בַבַּיִת, וַהֲרֵי הוּא כְמֵת וְיֵצֶר הָרָע פָּסַק מִמֶּנּוּ, תַּנְחוּמָא – Yitzchak was different because his eyes became dimmed and he was confined to the house, he was like dead and the yetzer harah already left him.
Maybe, the same can be said about Yaakov: Since he is in a state SIMILAR to death (as Rashi writes: נדמה להם שהוא מת – he seemed dead to them), it is okay to say אלקי יעקב.
Again, this is just a thought.
תן לחכם ויחכם עוד.