2. In Bamidbar 22:20, the Netziv points out that Bilaam was warned not to go עמם , meaning with them, but later he was allowed to go אתם, with them. Similarly, in Bamidbar 11:17, where Hashem was speaking to Moshe Rabbeinu, in one place it says ודברתי עמך instead of the usual ודברתי אתך.
The Netziv explains that imam means intending to do what they wanted him to do, with a unity of vision and intent. Itam, on the other hand, just means traveling together because your interests happen to overlap. This, Hashem allowed, because although they wanted him to curse, he ended up giving a bracha.
What changed? What characterized the Itam and the Imam?
Rav Schwab in the Maayon Beis Hashoeiva explains that the first time, there Bilam would have gone because he wanted to protect Moav and Midian, and his klala would be ‘lishma.’ When a person does something lishma, with sincerity, his effort will bear fruit. Even though the Ribbono Shel Olam was defending Klal Yisroel, if Bilaam would have gone lishma, there was a chance he could have managed to say a klala, and a klala from Bilaam that would be lishma would have been destructive, and so Hashem told him not to go. But once Bilaam revealed that his motivation was the honor and the reward he would receive, as he said in passuk 20, then Hashem told him to go, because then it was not lishma, and he didn’t pose a danger to Klal Yisroel.
We see from here that a person that works lishma can turn over the world, and can even subvert the retzon Hashem in this world at least for a time. To a great degree, historic events stem from the will of charismatic individuals. Every effort that is lishma will bear fruit— bichol etzev yehai mosar.
This is what the Chofetz Chaim meant. He was asked, why is it that the communists were so successful, and seemed to be taking over the world. He answered, Because there are among them a few that mean what they're doing sincerely: “וייל עס איז דא צוווישען זיי א פאר וואס מיינען דאס אויף אן אמת.” Those few that really believed in the truth of communism enabled that terrible and destructive and murderous movement to be so powerful and successful for almost a century.
This explains the difference in psukim referring to marriages. Koheles 9:7- לך אכל בשמחה לחמך, ושתה בלב טוב יינך: כי כבר רצה האלהים את מעשיך. בכל-עת יהיו בגדיך לבנים ושמן על ראשך אל יחסר. ראה חיים עם אשה אשר אהבת כל ימי חיי הבלך. But in Koheles 7:26, מוצא אני מר ממות את האשה אשר היא מצודים וחרמים לבה.
And this is why we make two brachos in the Sheva Brachos on the simchah: the first is chasan v’kallah, and the second is chasan im hakalla.
3. 22:18. Bilaam was considered to be avaricious. He said that even if he were offered a houseful of gold, he couldn't go against Hashem's will, and Rashi brings that this was evidence of his avarice, that he desired, and felt he deserved, a palace full of gold.
In an interesting coincidence, that at least will remind us of the name, see Pirkei Avos 6:9, where Rebbi Yosi
ben Kisma said
The question is, of course, where is the diametric difference between the greed of Bilaam and, lehavdil, the indifference to material things of Rebbi Yosi ben Kisma, evident in their almost identical statements.
But what I wanted to point out is that the name Kisma echoes the story of Bilaam who, the passuk says, was visited by the elders of Midian who came with magical items in their hands- Kisamim b'yadam. (22:7)
Eli sent a comment that I want to put in here. I've expanded his references where I was able to. His words are indented.
Re: עם vs. את -- I was bothered by these rules once, it is hard to apply them consistently. The Netziv you mentioned and הכתב והקבלה here in Balak say that עם is a stronger bond, unity of intent. This is along the path of Sefer Chasidim dictum on בחורים וגם בתולות זקנים עם נערים.
From the Sefer Chasidim:
`אל תערב בנים ובנות פן יחטאו. אז תשמח בתולה במחול לבדם אבל בחורים וזקנים יחדיו (ירמיהו לא יב), וכן ילדים וילדות משחקים ברחובותיה (זכריה ח ה) ילדים לבד וילדות לבד. וכן בסוף תהלים (קמח יב) בחורים וגם בתולות ולא אמר בחורים עם בתולות כמו זקנים עם נערים גם לרבות נשים לב
Maharal (Derech Avos on the Mishna of R. Yossi ben Kisma, see bottom right) goes in somewhat opposite direction, saying that 'א' עם 'ב' means that 'א' טפל ל'ב' (and that's why Rav Yosi ben Kisma did not accept the offer שתגור עמנו במקומנו).
However, this echoes Rabbeinu Tam (but not Rabbeinu Elchanan) in Tosfos Yeshanim Yoma 85b, and how the Maharsha explains וחי אחיך עמך - חייך קודמין
Trying to avoid typing the whole thing out, I found a very fine sefer (despite what some people said about it) that brings down and expands the Tosfos Yeshanim there, and who brings in the machlokes rishonim to explain Ben Petura and Reb Akiva on 62 :
(According to Rabbinu Elchanan, that in phrases of "A im B" A is more important, then יפה תלמוד תורה עם דרך ארץ shows that Torah is more important than a career, and ראה חיים עם אשה אשר אהבת refers to life, not the career, so it only means that life is more important than one's wife. According to Rabbeinu Elchanan, all we know is that Torah is more important than career, and life is more important than one's wife.)
ויקח משה את עצמות יוסף עמו or אם גנב יגנב מעמו - isn't אתו more appropriate according to the Netziv? Yosef indeed said והעליתם את עצמותי מזה אתכם.
Moreover, the Meraglim are called והאנשים אשר עמו (referring to Kalev). In Yehoshua, Kalev again refers to them as ואחי אשר עלו עמי These examples work better with the Maharal.
By Eliezer (when he went to find a wife for Yitzchak) we find first ורגלי האנשים אשר אתו and then on their way back והאנשים אשר עמו (here the Netziv approach might say that on the way there, Eliezer wanted to accomplish his mission, while the accompanying people just wanted to get home asap. On the way back, they all just wanted to get home)
However, (i) we find that when Yaakov is going to Lavan - וישבת עמו and then later וישב עמו and ויעבד עמו. This seems a problem to both approaches. (ii) Avraham and Lot - וילך אתו לוט and then ולוט עמו הנגבה. Then again וגם ללוט ההולך את אברם and once more - אחרי הפרד לוט מעמו. (iii) In shoftim it says by Avimelech ויעל הוא וכל העם אשר אתו and in the next pasuk ויאמר אל העם אשר עמו, and there are many more such examples. It may be possible to find a local explanation to all of these, but the exceptions seem to overwhelm the rule.