@marksmanmax Yeah, I agree with you. The pistols back in INS were effective because of the option of AP rounds, so the pistols in INS:S aren't in comparison.
You make a good point to keep the Quick-Draw Holster seperate. The analogy that @Max80 made can be applied to AP rounds, and I find that ridiculous. But it's not the exactly a mirror comparison since AP rounds pretains to damage against armored players than the speed of unholstering pistols with its damage and accuracy unchanged, so I don't fully agree.
I've seen your post going in depth with all pistols, very intuitive and analytical. I agree with you on almost all of them since I've been in a numerious amount of situations where I find myself using my pistol from both sides.
For the iron sights part where their suppressors are an obstacle for the Hi-Power and the M1911, imo they should stay as passive/physical downside for using a suppressor for the Insurgent faction's pistols. I remember that the Makarov from INS has its sights obscured too, but it's not much of a problem for me personally.
For the availability for extended magazines, as a long-time INS player, I believe that the extended magazines modification should only be available for Makarov, Tariq, and M1911/M45A1 for all game modes and have the rest have the extended magazine mod only for Co-Op. All of those pistols have a low ammo count in their magazines, so it's sensible to give them the modification to increase ammo in each magazine. The extended magazine for the GLOCK-17 is so ridiculous.
I myself like to keep my own suggestions easy to implement, change, or add/remove for whatever current rules/patches/bugs that exist for developers to take advantage over quickly and that I'm not so analytical myself.