Which "regs" are you referring to?   The statutes say nothing about it being unlawful to carry in a place that "charges admission."

No.  Of the states that require CCW permits, CO used to be the most liberty minded state.  This has changed with the new law pertaining to carry by a resident with a non-resident permit (which affects reciprocity, perhaps as an unintended consequence).  WY ranked second at the time, as I believe they additionally outlawed carry in bars.

The only place I can't carry a concealed gun is (1) an establishment where there are metal detectors at ALL entrances and (2) a school (doesn't include a University).

That's it.  

Obviously, if the theatre saw you carrying, they could ask you to leave, as could any business or property owner.  Refusal would mean trespass.  I'm going to go out on a limb and say that Cinemark probably would not interrupt you during the hail of gunfire and ask you to leave.

A cinema here in town has a sign that CCW is prohibited, and I ignore it.  Those signs do not have the force of law.

As for Aurora, while I am unsure whether a city can pass an ordinance that regulates open carry, I suspect that it cannot.  This has been tried and beaten in Boulder.

Any attempt to regulate concealed carry has been preempted.

In order to complete the picture of CO's gun laws (although unrelated to this incident), carry in a vehicle w/o a permit is unregulated, save for a different section of the code that pertains to hunting/fish and game, which prohibits a long arm from being chambered while in a vehicle.

I just checked the VA State Police site.I am so glad I am wrong on this one. Thank you for the correction, sir.

You made me go look again.  

It isnt gun-free by CO Law but it is based on the Movie Theater owners policy.  Very few places are gun-free in CO by law.

Is that a photo from the actual theatre?