By ‘us’ I’m assuming you mean the Jewish people, and specifically those living in Israel today.
You can’t cherry-pick God’s promises. Even if you accept those verses at face value, the promise is contingent upon the nation remaining faithful to God’s commandments. In the Book of Deuteronomy (chap. 28), God warns Moses:
Oh, yes. Here are a few examples, just from the first few books of the Hebrew Bible:
The most obvious instance of a checkpoint was the one set up by the Gileadites to catch retreating Ephraimite soldiers, after the Ephraimites’ defeat in battle. Since Ephraimites were known to have a particular kind of lisp—pronouncing /sh/ as /s/—the Gileadites put a simple test to every man they caught:
Then said they unto him, Say now Shibboleth: and he said Sibboleth: for he could not frame to pronounce it right. Then they took him, and slew him at the passages of Jordan: and there fell at that time of the Ephraimites forty and two thousand. [Judges 12:6]
[A2A] Because He was putting on a show, to demonstrate to the Hebrews* and other nations that He is the greatest—nay, the only—God.
This was, if you like, God’s comeback performance (His first since the Flood), so he was intent on making a big impression. And what greater impression could there be than to beat up and humiliate the most powerful kingdom in the known world at that time?
Samuel (in Hebrew, Shmuel) does not mean “God has heard”: whoever told you that may be thinking it’s spelled שמוע-אל, i.e. “Shmua-el”, but it’s not. The consonant ayin is missing, and it doesn’t go missing lightly.
In the story of Samuel’s birth (I Sam. 1), Hannah, his mother, explains that she named him so—
כי מיהוה שאלתיו (ki meAdonai she’iltiv)
—i.e., ‘because from the Lord I have borrowed him’.
Elohim was the name of God for the Israelite (northern) tribes.
IHVH was the name of the God of the Judeans (southern tribe).
Since both religions were based on the belief in a single, Creator, God, the two traditions were knitted into one when the refugees of the northern kingdom were absorbed into Judea following the destruction of the northern kingdom by the Assyrians around 725 BCE, at the instruction of the Judean King Ezekiah.
This is one of those fun questions, like “Mummy—how do babies come into the world?”, or “How does Santa deliver our presents when we have no chimney?” The actual history is a lot more prosaic but more interesting than the pat answers, such as that the Hebrew words for water (mayim) and sky (shamayim) are also seemingly plural but are not (actually they are, as they use plural adjectives as well, and if quacks like a duck and waddles like a duck—it’s a duck). Talmudic tradition of centuries of pilpul is capable of much greater feats than that—such as why placing restrictions on women is really a sign of respect, or why there are several different answers to what happens when Two Men Come Down The Same Chimney.