What should I do?

I'm so sorry you're experiencing health problems with your dog. Our family dog developed spay related urinary incontinence even though she was spayed at 1.5 years (she was from a rescue). But it was well controlled on medication and wasn't really an issue when treated. It has been a well known side effect of spaying for a long time, and usually it's a minor treatable issue. It sounds like your issues are more severe than are normally seen though. Is she on medication for the incontinence?

I think from earlier threads I can see she's originally from Ash's Mystical which is generally considered a good reputable breeder. Have you contacted Ash's about it? The difference between responsible breeders and bybs is that responsible breeders try to carefully breed for health and temperament. They do genetic and physical tests for all conditions they can, but it's still possible for recessive conditions to pop up that cannot be tested for. When this occurs, good breeders rely on puppy buyers to notify them so they can try to eliminate any carriers from their breeding program. Bybs don't do any of this, and breed dogs based only on the money they will get from the puppies. I don't really see how you're coming to the conclusion that reputable breeders are somehow worse than bybs.

I looked at the breeder website and they do still seem to support early spay/neuter though I can't see the actual contract. For me personally, that would be unacceptable, though many people do still choose to fix dogs at six months without obvious major health consequence. But it's a controversial issue and you will find breeders have many different stances on requirement of neuter and when it occurs. It's more of a thing that a buyer needs to decide upon before they purchase a puppy from a given breeder.

I have seen other very reputable breeders discover that one of their dogs is a carrier for epilepsy, and they remove them from the program. It probably takes more than one seizure to be sure of a diagnosis, but if I was Ash's I'd definitely want to be updated and given a chance to respond. The other issues may or may not have a genetic component, but it is something a breeder would want to track in case it is genetic.

EDIT: After reading through Sophie Anne's thread, it looks like the issue resolved and unless it is repeated I'm not sure it's evidence of a genetic problem.