Vayeilech, Devarim 31:12. The False Dichotomy of Tzibur/Yachid

The Mitzva of Hakhel is stated thus:
הקהל את העם האנשים והנשים והטף וגרך אשר בשעריך למען ישמעו 
Gather the nation, men and women and children and converts that live among you so that they will hear....

To whom was Moshe speaking?  Who was commanded to fulfill the mitzva of Hakhel?  The answer to this question is not clear to me.  In pesukim 1 through 6, Moshe is speaking to all of Klal Yisrael.  In pesukim 7 and 8, he is speaking to Yehoshua.  In passuk 9, he is dealing with the members of his shevet and Sanhedrin.  So when passuk 10 begins, and it says ויצו משה אותם לאמר מקץ שבע שנים במעד שנת השמטה בחג הסכות.  בבוא כל ישראל לראות את פני יהוה אלהיך במקום אשר יבחר תקרא את התורה הזאת נגד כל ישראל באזניהם. הקהל את העם, when it says ויצו משה אותם, who is the the  אותם?  Who is he instructing?  If  אותם is Klal Yisrael, then it shouldn't say בבוא כל ישראל, when Klal Yisrael will come.  It should say בבואכם, when you will come.  If, on the other hand, it is directed to Yehoshua and the Zkainim and Shevet Levi, then the pesukim flow more naturally.

Anyway, I can't see in the words הקהל את העם any commandment to individuals.  It seems like a mitzva that the people should be gathered, not a mitzva for the individuals to gather.  By Aliya Laregel, on the other hand, the words are שלוש פעמים בשנה יראה כל זכורך.  The various terms used in that context are יראה, תחוג, and ושמחת.  These are not at all like הקהל את העם.  

In fact, the Rambam's words (3 Chagiga 1) are מצות עשה להקהיל כל ישראל.  In the next halacha, he says כל הפטור מן הראייה פטור ממצות הקהל, which might be read to mean that there is an individual obligation, but I don't believe that's true.  It just defines who is to be gathered.

The Malbim here says הצווי על הב"ד שבידם להקהיל כולם, so there clearly is a mitzva on Beis Din.  But his next words are ועל כל איש מישראל על מה שבידו לבא בעצמו ולזרז הנשים ולהביא את הטף, that there is also a mitzva on each individual.

Where do we get the mitzva for individuals out of this passuk?  The אותם in ויצו משה אותם can only have one meaning; either it means Beis Din or it means each individual.  How can we say it means both? 

The assumption of my question is that the tzibur is not the yachid and the yachid is not the tzibur.  I think that the dichotomy between the individual and the tzibur is false.  Our perception of ourselves as individuals is illusory.  The isolation of consciousness is an artifact that bespeaks a limitation of perception, not a reality.  For all I know, white blood cells might have some kind of awareness, like that of an amoeba, and act as if they're independent.  But they're not; they're component units in an organism which have no significance as individuals.  I think the same is true of Klal Yisrael.

Even if one were to postulate some kind of collective moral sensorium, that our experiences and actions influence others without our or their realizing it (as Reb Yisrael Salanter said- "If someone says Lashon Hara in the Beis Medrash in Vilna, there will be more chillul Shabbos in Paris", or as the Ibn Ezra says by Egla Arufa in Devarim 21,) that would only make sense for contemporaries.  Avraham Avinu's words resulted in the suffering of Shibud Mitzrayim, and his merits benefit his descendants through zechus avos, even though we are not responsible for what he did and not control him.  The Tzibur affects the yachid and the behavior of a yachid has an effect on the tzibbur, as Rav Freidlander discusses in his Sifsei Chaim in the section Ein Mazal LeYisrael, as does Rav Meir Berman in his Sifsei Daas II on Haazinu.  (Rabbi Dovid Gottlieb, writing as Dale Gottlieb, wrote an article on this question many years ago in Tradition.  I found the article stimulating but far from comprehensive.  If you want to pay for it, it is available here, but you're not allowed to share it.)  Famously, the Rambam in Teshuva says that one individual's behavior can tip the balance of the entire world and create consequences for all the members of the tzibur.  Even if the mitzva is to Beis Din, that only means that it 's a mitzva on the tzibur.  Tzibur and individual are identical.  The covenants, and the renewal of covenant, was with כולכם- the people as a whole- Mattan Torah, Nitzavim, and Hakhel.  The deeper truth is only the כולכם.  I also believe that the כולכם usually applies only to Klal Yisrael, but might to some extent apply to mankind as a whole.

I realize that this extreme postulate would mean that there is no schar or onesh for individuals.  That is absurd, but I don't know where to draw the line.  If individuals suffer for the behavior of the tzibur as a whole, and vice versa, then the idea of pure personal self-determination is not correct.  Maybe individualism and national organicism, or holistic collectivism, are not mutually exclusive; maybe each reality is fully functional, but I can't figure out how that would work.  It seems to me that the former contradicts the latter.