Drip is VERY important, id rather wear a nice blue mailman uniform than a red one as sec, and i much perfer to wear a white labcoat as a forensic tech, both choices make me less of a target and look nice.
Forced uniforms can be a thing on a HOS by HOS basis just like any other department, but an SOP line MANDATING such an act i feel would work to the detriment of peoples experience.
As for undercover officers: Its a legitimate tactic, so i dont see why it would be removed. It seems almost like alot of antags feel entitled to as little resistance as possible during any action they may take, be it a civilian pulling someone to safety, a legitimate act of workplace self defence from co-workers or an officer who hid in a potted plant or locker to jump the bad guy at the right moment or even something as minor as a random civ just being in the wrong place at the wrong time by complete chance, and they just happened to run into them, slowing them down for only a second or 2, but that being all it took for security to catch up and nab them
As an antag, expect the unexpected, plan for failure and roll with the punches