You mention several good points but I'd like to suggest another component, one that IMHO plays a large part, and that is exclusivity.
The Exclusionary Christians believe they are the Elect, the Chosen, the Winners. They see themselves as an exclusive little group with something no one else has.
They belong to this little club, and no one that is not in the club is saved. They KNOW they are right, everyone else is wrong, they are above and beyond the rules, restrictions and evidence that eveyone else must live under. The club is even smaller and more exclusive because they wilfully exclude not just non-club members, but even any other chapter of the club, or any other individual that they disapprove of. They spend their lives pointing out those other members of the club that are not TRUE club members.
Aslan is not a Tame Lion