As much as I truly despise Trump I really doubt he will ever spend a single day in prison. I'd be relieved if at least he was prevented from running for office ever again.
I figure, even if he's indicted and convicted. He can drag it out for years in appeals. Or get a fast track to have an appeal, thru this Supreme Court. His court. He should die in prison. But I doubt that will happen. You're right, the best hope is him being barred from ever holding public office again. And hopefully all of his co-conspriators too.
On #3, Stone had a relationship with both the Proud Boys and the Oath Keepers militias. It was never believable to suppose Trump didn't know guns would be and were be present. Being armed is what 'militia' means.
As for prosecuting Trump, apparently these shitheads are putting out the notion of "Prosecutorial Discretion" wherein a decision to prosecute includes consideration of "what is good for the country." What that translates into is that the compromised DOJ can dismiss justice in favor of maintaining a tiered justice system. (Maintaining immunity for the wealthy who have bribed DOJ officials who are so badly underpaid, and support Trump).
USA-RIP