I think ideally, every SRB2 shield should have an interesting and useful passive AND active ability. Doing this without overhauling the shields too much would require adjusting both the shields and the levels themselves.
Whirlwind: Perfect as is. I think the jump from falling or springs qualifies as a passive ability, but if it doesn't, the best I can think of is protection from hazards that slow you down. Like Canarivore breath and mud, perhaps also the ability to run on goop and in water at normal speed so it's useful in more levels.
Attraction: Make the homing attack chainable (already merged into 2.2.9 I think), keep the rest as is. Maybe also make electrical damage more prominent in SRB2 levels; right now, it's only a thing in Techno Hill.
Elemental: Passive can stay, but the stomp would really help if it felt more like a STOMP and not just a fast drop. Maybe make it have a wider radius for enemy damage or otherwise smash things to the ground. Also might be good to remove or decrease the momentum reset. I don't think the shield should be able to break floors, since right now breakable floors serve for character path splits.
Force: I think protection from two hits is a lackluster passive ability; I have to wonder if spike/sharp thing protection would serve well for this shield, either along with or replacing two hits. Protection from not just spikes, but also cacti, maces, sharp parts of enemies like green snappers or spincushions, and likely other things I'm forgetting. As for the active ability, Katmint's momentum pause is still easily the best one I've seen. I'd much rather have it oriented upon movement than combat.
Armageddon: If this shield were to stay in SRB2 in its current form, then it would be a LOT better if the game had more secrets you can only, or by far most quickly, access using an armageddon shield. Right now we have the crawla cage in GFZ1, a few score chain combos with mines in DSZ1, the club emblem in ATZ, and not much else. It would be nice if every level in SRB2 either has a secret or two you can only (or most easily) access using an armageddon shield, or doesn't have any armageddon shields. I kind of like the idea of having the armageddon shield be a useful way to collect further secrets. Think like doors you can only open by bringing a nuke to activate a switch or set off locked-up TNT.