For the love of all that is holy, please don't use Armor All-type things anywhere on a vehicle. Ever. tl;dr it causes rubber to dry out and affects plastics long-term3) The rubber beltline trim surround on the doors are composed of some sort of rubberized plastic. Should I start applying a protectant/Armor All-type applicator to protect it from fading? If so, are there any recommended cleaner/application treatments that work best for this type of material that would not damage the paint?
(longer explanation: Products like Armor All are usually oil-based. They end up 'pulling' the embedded oils out of rubber and plastic, drying them out over time which leads to cracking, discoloration, waxy/greasy residue and so on)
I personally use Gyeon Tire for both my tires and the rubberised trims around the car. It's silicon-based which has the added bonus of being water-repellent. When applying to the trims I put a relatively small amount on a microfiber cloth and run it over the trim, leave it sit for about ten minutes then come back and wipe down to remove any residue. It's very much a less-is-more product. I'll do this every 3-6 months or so
Another option would be something like AMMO Mud - it's water based and works well, but doesn't last as long as the Gyeon