You haven't "demonstrated" anything, actually. Barr and Mueller agree on one thing - that the president had interfered with the investigation in a non-official manner, which doesn't necessarily mean that he intended to obstruct it, or obstructed it at all. It's not a "scattershot" approach, I'm explaining to you certain holes in your reasoning as they come up. It's not even an argument per se since there's nothing to argue about - no prosecution is going forward, and it's unlikely that that's going to change anytime soon, if ever. As I mentioned before, I'm not particularly bothered by what happens to Trump once he's no longer president, his period of usefulness is his term.
EDIT: You also keep using the word "fired" in reference to Mueller - Mueller was never actually fired. You can tell by how he completed the report. If Trump wanted to fire him, he could've, at any point, and at his own discretion, at which point he would've Nixonned himself. I haven't "argued that it wasn't an obstructive act" - it never happened, I couldn't argue that if I wanted to. As I said, he was frustrated and said a bunch of shit. At no point did he use his executive privilege to put an end to the investigation in progress.