Yes, the best way to respond to "tangents to the actual discussion" is always more tangents to the actual discussion.
If you wish to refute with actual information then its quite simple.
As a private party they have the ability to restrict on any non-protected grounds they wish. Gun ownership is not a protected class. If you attempt to enter with a firearm they can ask you to leave.
If you do not leave then you're trespassing, which is a crime, and they can call the police and arrest you for it. This is not complicated, it does not require looking at what the city can and cannot do, it barely even requires looking at gun laws. If security asks you to leave and you do not (and they don't have a bad reason for asking you to leave) then you have to leave. And if you don't, you're breaking the law.
If you attempt to bring weapons to PAX you will likely be turned away, if you persist, they can bring in the force of law to prevent you from entering. If you persist more you may be arrested for trespassing.
Perhaps the discussion on consealed / lawful carry should be taken to the debate & discource forum. It doesn't really fit here.