To the OP, this is one of the best overall summaries of our defensive issues that I've seen. I'm not a coach but played some and have family with decades of coaching experience. We've discussed exactly some of the issues you brought to light with the ILBs and pressure packages. Awesome insights.
Only thing I'd add is that our safety play has been hit or miss as well, mostly from a technique standpoint from my view. The youth of our corners has shone through at times (to be expected) but overall I think they're actually making progress. Safety, however, hasn't been nearly as consistent as I'd hoped or expected.