That’s a good list of cues! But knowing the cues and understanding them are very, very different. You have to practice with razor sharp focus and great intent and realize what those cues mean. And even once you feel proficient in the movement, every so often you’ll hit an epiphany that brings one of those cues to life.
At some point, with enough deliberate practice, you will understand what it means to screw your feet into the floor. You will understand the sensations, the tension, the strength that initiating the movement through the hips creates. The weight distribution will start to make sense, the breathing will start to make sense, but no amount of reading will fill in the blanks completely.
But now my question is what are you doing daily to open up the front of the hip? It is as you say, that stiffness in the front of the hip can shut the glutes down, or at least make them very difficult to activate. What is your plan for combating this issue? If you don’t have a plan of attack, then that is exactly what we need to put together. Only through consistency will you be able to decide if and why your approach is working.
Also, it is important to realize that movement technique is not an all-or-nothing thing. If you are a mindful athlete, you will be optimizing that technique for the rest of your active life (which will hopefully be all of it). If you’re missing a significant amount of your range of motion, of course you won’t be able to squat perfectly, or very deep. But you can always do something. Fixing your mobility issues won’t magically transform your squat. All it will do is provide a window for greater improvement.