Good analysis of the archetype and I like your decklist with a couple exceptions in ice selection:
First, x2 Ice Wall and x2 Bastion. Considering you have GRNDL, Grim, Hostile Takeover, and Geothermal Fracking, Bastion isn't going to tax the runner. Maybe it would work with Veteran's Program, but that would require a weaker agenda choice and the right draw order. If you really want high-strength barriers, Ice Wall is the way to go. As a perk, you can prevent slow parasites, Morning Star, and counter Atman too. There's no reason to at least go x3 Ice Wall x1 Bastion, but I think a better mix would be x3 Ice Wall x1/x2 Wraparound (AI kills Chimera and your light destruction theme). The fact that you can save 3 credits by using Ice Wall makes it an easy choice.
Similarly, I'm not convinced that Enigma is better than Quandary in this deck. Enigma's main advantage over Quandary is punishing early breakerless runs. Most people aren't going to run aggressively early against a scorch deck, instead searching for plascrete and economy. Quandary saves 2 credits per rez and does effectively the same job, especially in this deck.
Guard is an interesting card because it protects against a very narrow category of runner cards (Inside Job and Feint). Feint isn't anything to worry about, worst case scenario is Silhouette exposing your only Junebug which wouldn't happen enough to build around. Inside Job is a nasty card and Guard is good against it, but only if the runner doesn't already have a sentry breaker. Instead, you might consider another 4-cost ETR sentry like Rototurret or Fenris. I would go with Rototurret because of the lower influence and synergy with program destruction.
Finally, a note about Jackson Howard. He doesn't win games outside of the accelerated diagnostics combo (Which you are thankfully not using). He does however, prevent you from losing some games. Jackson Howard reduces variance and increases consistency with both of his abilities. On top of that, he is great at recursion when combined with Project Atlas. I would probably switch identities because of the need for more influence for all of my recommendations and play at least x2 Jackson Howard. You make a good argument about Power Shutdown, but I don't think Punitive is better in this deck. I would include at least 1 Power Shutdown just so the runner is forced to protect against it.