They are all valid reasons, but I don't think they were the actual trigger.
Remember when a few weeks leading up to the invasion, Biden continued his rhetoric that Putin was going to invade Ukraine and had amassed a large amount of troops and tanks on the border. Equally, NATO had also moved troops closer to the border with the exercises taking place with Poland. At the same time in the Donbass region there had been a significant increase of shelling coming from the Ukraine Forces in that region. They too had a large contingency of troops gathered in that region. The previous few months had been relatively quite.
Just a couple of things to note. Putin has the final say in the decision making process. However, just as with Congress in the US, whereby Biden also has to confide before making important strategic decisions, Putin has the Duma to contend with. A few days before the actual invasion a number of things took place. Denis Pushilin, the head of the DPR had signed a decree for mobilisation of the Donetsk region for civilians, as there were fears that the DPR were going to be over run by the Ukraine forces. He also made contact to Russia outlining his concerns that they desperately needed help as they did not have enough manpower to hold the line. Pasechnik also signed a similar decree for the Luhansk People's Republic shortly afterwards. IMO, the major reason to the invasion came when Zalensky publicly stated that they were going to liberate the region and already had the forces in place.
A tell tale sign of the invasion was when Putin gave his speech a couple of nights beforehand. In his speech, he had reiterated his disappointment at Zelensky for not following his election promises of ratifying Minsk2 agreement. Putin made one final comment IMO that sealed it. He lamented that Russia had not gone to the aid of the DPR earlier on in 2015 when they were calling out to be separated from Ukraine, similar to what happened with Crimea at the time. The Donbass people expected Russia to come to their aid and they didn't. Many thousands of civilian deaths over that period from 2014-2022 further on would have played on his mind, when considering he had the power to change the course of history and we may not be even discussing it now. That is the tragedy.
I also believe Biden set a trap using Zelensky as the puppet. What better way than to entice Russia into war? It wasn't by accident that there was a monumental shift with a decisive increase in shelling as well as the increase in troops. Add to that the rhetoric coming from Washington and it only left open two options for Russia. Allow Donbass to be completely over run by Ukraine forces, not knowing where it stops from there. The alternative was to take a stance against the West and NATO, knowing full well that sanctions would be imminent and would be far reaching for the Russian population as a whole.
Contrary to the populace view, I believe he made the correct decision if he ever wants to breakaway from the Unipolar world. Ukraine had many opportunities to prevent Russia from going down this path. However, it was through weak leadership by the Zelensky regime to be so enslaved by the hands of the US Policy makers that could have chosen a different path by signing the Minsk Agreement.
