If you remove the lock cylinder then you don't need this product at all. This product is only to prevent grabbing the cylinder from behind the handle to forcibly rotate it, allowing entrance to the vehicle. If you remove the cylinder, then there's nothing to rotate. Then, as you mentioned, find the plug from somewhere to put in the left over hole in the door (could probably also get a handle from a junkyard if you want to cover the keyhole in the handle itself). So besides not needing #4, everything else looks good.
The issue is, and I think why a lot of us liked this product, is that me personally, I want to still be able to use my physical key in the event I'm out rural and my batteries completely die. I mean, for the key fob or door keypad to not work, those batteries would have to be extremely dead, but I have a jumper in the car. I want my physical key to still work.
If you don't care about that, then yeah, I'd be pulling the lock cylinder all out, and making the door a barrier. Then, as you also said, only way to get in is break glass, which really is a deterrent for most (not the little break to pull up the lock, but a big break to have to reach a hand in to unlock the truck)
I dont' want to setup remote wires that can be used to attach jumper cables and give enough juice to open the doors. And if you're way out there all alone, I also don't want to have to figure out a place to store a secondary power source outside the truck, to then use on the cables I ran to jump the truck and allow my to open the door. Everything I need to get home is in the truck. I just need to get in the truck.
So after removing the lock rods and covering those holes, I will have some good layers of security to prevent opportunistic theft and full theft of the vehicle. The only way to take my truck, is a tow truck. I will cross my fingers and hope this never happens, as I don't want a 2023 model! haha