First Bold, I ve never lifted in o shoes so I cant comment, but if your lifts are going up due to the egronomics of the platform which is raised heels then that was my point.
Question on second bold, why 90%? my point was the plates put the feet in a better position to push through the heels. but if they are not needed and dont add to the ability to move more weight then I would think it would be eaqual lifting shoe (angle) vs barefoot (no angle). I am not being an ass, just analyzing here. Also I aree you should do a set flat footed from time to time. But notevery time you work out.
Bold 3 this I agree on 100% the hip flexors and groin make a huge impact on squats. The deeper you go the more impact.
Last paragraph, thats a joke. Because someone uses workout shoes does not mean they have a mobility problem, it means they prefer a platform of another. Hence you choose to do your reps in workout shoes instead of flat footed. You prefer that platform over another. That does not mean the next person in Vibrams next to you has more mobility. It means you have two different ideas on your platforms.
Your "call out" is wrong. Mobility may be an issue in some people but the fact one platform is prefered over another does not mean there is a fault. I am first to admit most my workouts are about building a better looking body, I dont care what I can move (ecentric anyday), but legs are different. I thrive on doing legs. It my personal favorite, Its my goal to have great quads, hams, calves, flexors; especially in competing. When I can lift my shorts and show my leg match the body builders I love it.