I'm not sure. There are the points you address to his favor, but on the other hand, he uses deceit to overcome his enemies (the gun taped to his back in Die Hard as an example, which arguably he needed to use to get the drop on the bad guys), shows no mercy (of course, that's Hollywood for you), and is very much the everyman in archetype. So, I'd argue that he has more in common with a yeoman in the vein of the Robin Hood than a knight, doing that which he feels is right, but not always in a way that is an exemplar of knighthood.