To answer both of your questions:
1) Yes, Red was able to carry his rifle past security to the front gate of Disneyland, a place where you’re not even allowed to carry selfie sticks. Why was he able to do that? Because this is a work of fiction. That’s why!
2) Yes, I did rip off the main joke for this comic from Freakazoid. What can I say? It was one of the most underrated shows of the 90s!