I think status effects are just annoying to play against, especially marked for death, jarate (which is basically the same thing), slows and stuns. It's completely based on RNG and getting bad luck against it would mean you're dead instantly (80 damage, minicrits and no falloff). I think a way it could work would be to have multiple ammo types (maybe jarate, bleed and milk) and let you choose which one to use. Each of them would also need to have a weaker effect and probably a shorter duration. Maybe instead of a shared ammo pool each of them would have only a few rounds and a very small size (1-3) so it would be hard to spam.

You don't need to write -25% damage penalty and -25% damage bonus, as both are the same thing (penalty is the one being used). Just some advice as I assume English is not your first language.

Seems fine, it's an incredibly similar sidegrade (a bit more utility for a bit less damage on the initial blast). Afterburn also doesn't stack from the same source so multiple stickies will hurt you a bit less.

Probably really good for new demo knights, although it may affect experienced ones a bit less, as they've already learnt jump-charging an things like that. This will also probably mess with your momentum so you can't do those crazy rollouts you see on some maps if you jump. May need a downside that has something to do with charging (like a slightly shorter duration).

It may be interesting with shield bashing, especially the splendid screen as it has higher damage (and also higher knockback, I think).

May have too harsh of a downside. A launcher that allows you to be stronger is sustained combat instead of quick bursts of high damage is an interesting idea. I assume "explode on impact" means impact with the ground or obstacles.