if the election was stolen ... Trump’s actions to retain power were not only justified, but also imperative, and very much within the scope of his duties as president

Nope this doesn't follow. It would just mean that both actions would be equally illegal. There is no provision in law for one to break the law in order to remedy breaking the law.

you can argue there’s room for “better to ask for forgiveness than permission” in that context.

This actually basically never applies in real life. In real life we let the criminal off rather than incentivize breaking the law by declaring evidence so gained as fruits of a poisonous tree.

If you’re not sure whether there’s been a crime but there’s a massive time pressure and extremely high stakes (as would be the case if the election was actually stolen), you would need to act as if there was a crime

In the almost mythical stereotypical ticking time bomb scenario where morality can only be served by breaking the law the right thing after the bomb is diffused is to attempt to punish both cop and criminal. The cop in that scenario isn't above the law their actions are a willing sacrifice of their own well being in service of a higher good.

if you investigate, and there’s a crime, you’ve saved the world; if you investigate and there is no crime, then you will go to jail for it. That’s a bit unfair – so, a warning that, if you investigate this and there’s no crime, then you’re going to jail, might’ve been called for.

He did investigate. There were 60 some cases including in GA. There was a recount and so forth. None of this was a crime.

The crime was threatening the SOS and trying to get the SOS or other officials to "fix" the election after he lost. The crime was getting fake electors to swear on lawful papework that they were lawfully chosen electors.

None of this is even slightly legit. It is as obviously illegal as dealing heroin or hiring a contract killer. Nobody is required to discern the nature of your criminal conspiracy and warn you that you are plotting to commit a crime.