Could get interesting honestly. Striker's being on a timer is good, however, I would propose the health to be a pip related thing, not aa HP trinket one. If you are at less than 5 pips, then you will enter berserk mode for 5 seconds. If you somehow get lowered to less than one pip, you would be eternally in berserk mode (until healing). Berserk only happens once per life, however the less-than 1 pip one can be activated multiple times per life.

If someone is willing to reduce themselves down to half a pip as a striker, where any single bullet will kill them, and they decide that's their new playstyle... Then well, it might open up a new world for strikers. I can see some running in lower-star gear to lower their overall health so that they will enter that mode normally. I would also say, to level the playing field, both berserk modes increase damage bonuses to "MAXIMUM" (with the added damage boost buff), increase MSI to "high", and increase CTR to "MAXIMUM". This means both a chaos and a black kat user will be on par with each other, and even a cobalt user will have the exact same buffs.

This introduces an all new version of a glass cannon, where you play at very high bonuses, but a single hit from anything will kill you. Guns become a swordie's weakness, and a fire bomb means death. This may even increase low-health strikers on the field, so instead of retreating back to base they will continue to fight. If a guardian heals them, they lose the bonus.

Recon, I would say yes to that ability. However, it doesn't change how a recon plays per-say. I would say have recon shields able to absorb all statuses from a status bomb... Or, heck, from any source. However, upon leaving cloak, you are inflicted with every status that you should have been affected by while inside. This means, the longer a haze bomber keeps up, the more you can stay on their point, deathmarking them for allies. If you try to exit and attack, you'll be in for a world of hurt. Hope you can find a safe spot to be shocked!
This does, however, mean that UV rollers will be able to sneak up on haze bombers. But in all honesty, if you're a UV-hazewalker and playing recon, that's something different in-of itself. All the haze bomber needs at that point is either a gun to find the recon, or a blast bomb thrown into the mix to keep a potential sword-recon out.

Lastly, guardian shield ability is yes. I would also say every time the shield protects a teammate from being hit, the guardian shield heals everyone inside of the shield equally for half the amount of damage the attack would have done(100 damage heals 2 players by 25hp, 4 players by 12.5hp, etc). This means you want to break the guardian shield by hitting the guardian, not attacking their allies. I would also say attacking a guardian with a dead shield (which is still up!) will heal teammates within the shield radius for 75% of their health lost, not spread equally (i.e., if a guardian had full health and has 3 strikers within their shield and you kill the guardian, now all strikers will have full health again).
This makes guardians more of a medic class that needs to be focused on, however once defenseless it might be better to take out their protectors. Once the guardian lowers their shield, even when broken, they can become your target.

Yes, I pretty much turned your ideas into more extreme versions. I agree with your original idea, however these sort of passive abilities would make each class a deadly force rather than them being "striker and not striker", which is really the biggest problem in lockdown.

I think it's good to have an extreme and a low-end, so that we can settle somewhere in the middle. Both ideas are good for the game, Holy-Nightmare's just keeps the game more close to its current state whereas mine brings a new kind of rush to the game that isn't just "buff class X" or "nerf class Y". One solves a few small problems, mine is a bit of a new state to be playing in.

I could make a "real problems" thread over in the coliseum sometime, addressing what some actual underlaying problems with lockdown is outside of what people complain about.

It is hard to throw balance around while keeping the game fun and all.

Immunity to haze bombs is only until they release. Did you get inflicted by shock multiple times? Well, have fun being spasm-mcgee over there. At the very least you can move haze bombers off the point, and make them have to do more than just haze bomb. If you come out of shielding in the haze bomb, you're now inflicted with that status, and much more.
I also say it is immune to all statuses. This means that a brandish charge would not inflict a recon who is cloaked, however it would still damage/reveal them for a moment. When they come out to fight you can expect them to be in a not-great condition. This makes recons rely on their cloak even more, however it prevents the cloak from draining as much.

But I do appreciate your bit of input on the guardian shields. It is a lot of healing, and that can be problematic once you get multiple guardians together. The good thing is that guardians would be doing more shielding and less attacking in that case, so the aggressive guardians don't feel much of a change, but new-guardians can benefit their team even in death. An all-guardian team might be a bit overkill, but by golly 6v6 guardian matches becoming meta would be so much more interesting to watch than 6v6 striker. I'd rather there be a bit of thinking "should I attack and assist my team, or should I give my life so that my team can hold down the point?" be involved rather than "oh shoot my shield is down now to aimlessly attac- oh gosh they have flourishes, and I can't attack, and I have so much health an- oh now I'm dead, great".

Two guardians shielding each other will only work so long. The other team can single out one guardian, and if the other guardian puts their shield down, then it's not all that different from our current fights. An all-guardian team might sound good on paper, but in execution, it is only as good as the players. Guardians that are aggressive lose their new shield abilities, and guardians that are only sitting ducks aren't helping their team beyond delaying the inevitable.

I guess what I'm saying is making every class OP makes them all balanced, and at the same time have a much better view of what they all are really for. If you give every class barely any difference between them, they all blend in, and if one stands out then that's the class everyone will be playing. In TF2, everyone wants to be a good Spy because it's the class that sorta stands out. Only problem is that team spy is easily destroyed by a single pyro. Not the case with team Striker in Spiral Knights.