All of your suppositions, I believe to be correct. He could be re-elected if the facade of a great economy can be maintained, and if there is any division in the concerted opposition to his re-election. If so, he will not even ever be subject to some laws that he has broken, because the statute of limitations will have run out. While he is POTUS, and thus controls the “Justice” Department, he cannot be accused of a crime by them, per policy. Hence the Mueller report, which, ironically contains quite strong evidence of Obstruction of Justice, could not indicate that he had committed the crime.
And the impeachment process, available under the Constitution, cannot remove Trump from office because not enuf Repub Senators will vote for his removal. Also, the Constitutional responsibility to oversee the executive branch, may also be moot, as Trump opposes every effort of the House of Representatives to attain any info that might incriminate him. It is not legal for Trump to simply refuse to turn over info, but he seems to have decided to see how long he can get away with not turning ANYTHING over. And he may be able to run the clock out until the next election, or until the public may perceive the Congressional efforts to be unacceptable. He has a rock solid base of close to 40% of voters, so he only needs to sway a relatively small additional % to believe his persistent, ubiquitously repeated, false narrative. He is above the law, the desire of every eventual autocrat. It is no longer beyond reasonable conjecture that Trump could become the USA’s first Dictator. But that is still a longshot, I hope.