You can withstand multiple gunshots at point blank range, right from the start, and that's even the squishiest ATs. That armor Stark used to escape the terrorist camp was, in fact, Iron Man mk1. He even has to revisit this armor in a few comics. I'm not sure what your reasoning is to say that "The Kitty Pryde in X-Men who ran through the wall was not Shadowcat" - it absolutely was. Yet at the same time, a single gunshot would kill her, if she didn't time her phasing perfectly. "Superman" was just the moniker Clark Kent adopted in order to protect himself and those he loved, while he was superheroing. Now, you could argue that "Clark Kent" was always the moniker, and "Superman" is his true identity, but my point still holds - Clark Kent *is* Superman, (not including one of those alternate realities or "what if's" where they are actually separate people in some literal way).
If you don't want to defend your position anymore, that your prerogative, but don't pretend to think that only you have the correct perspective...