So the fact that the FBI warned the Capitol Police days in advance they were picking up chatter about a planned attack on the Capitol - that doesn't blow the whole incitement thesis out of the water. Or that some demonstrators were trespassing and pushing against barricades before he finished his speech? Doesn't the fact that Trump asked the crowd to make their voices heard "peacefully and patriotically" mean there is no case of incitement at all? Trump condemned the violence.
When BLM-Antifa mobs attacked the White House this summer and injured 60 Secret Service and US Marshall personnel, Democrats did not call it an attack on the Constitution and did not condemn the violence. Should they be impeached for incitement?
A lot of the problem here goes back to the rushed nature of the impeachment. There is no evidentiary record. There is no timeline. There were no witnesses deposed, sworn, and cross-examined. As more facts come out, they undermine the so-called clear cut allegations.
The whole proceeding of having an impeachment trial of a private citizen is unconstitutional. If he is criminally liable, he can be charged, tried, and convicted in a real court of law, as the Constitution says. But that will never happen as there is no case.
By the way, I agree with your overall insight that Trump is looking at this as an opportunity to argue his case and make a big splash. The Democrats are idiotically giving him a big platform to present all kinds of evidence about voter fraud and highlight illegal changes in voting rules.