I have to say this is one of the more constructive suggestions that doesn't simply turn back to the Saving Throws system of D:OS1, so props for that. You seem to be focusing on the aspect of character building and interactivity in combat, which I think definitely advances the design philosophy of combat and the armor system in a way everyone can appreciate.
The idea of Delayed CCs is a fantastic one, and I think that introducing them as you've described would help introduce another layer of depth to character building and combat; a Delayed CC is far more interactive and seems to suit the current Armor system very well. Having to account for, manage, and react to these CCs rather than wholly diving through the DPS race sounds like it'd be a lot more engaging.
I also agree that there is a major lack of skills that actually INTERACT with armor outside of the binary yes/no resist system. Abilities that have different effects based on armor, work better against armor, and so on sounds fantastic.
Hybrid Damage and Piercing Damage is also thoroughly underutilized, and I feel like even the weapon statlines could better represent them with their untapped potential. Even abilities that make use of Piercing damage or target off-type defenses are scarce or underwhelming (Scoundrel abilities are the largest offender, personally).
