Actually, you can train a cat to use a human toilet if you can't stand the litter box. It takes a few weeks, but it can be done. The only disadvantage to training a cat to use the toilet is that you have to keep the toilet seat up so it has access to the toilet, which can be a problem if you have small toddlers. Just look up "Toilet training a cat" in the seach bar and you see kits and instructions for doing it.
That said, both of the cats that I've had didn't seem to mind that the litterbox was often dirty (not overflowing, but often stinky and with poops) and didn't go outside of the litterbox. I think it depends on how the cat was raised. If one is a staunch neatnick then the cat will be too, they won't have developed the tolerance for the occasional mess. I was often one of the people that tended to scoop the litterbox about one-two times a week, usually only doing so when the smell became intolerable. But the cats didn't seem to mind, and the only time one started to elimiate outside the box was when he was getting old and seemed t lose the tolerance for the smell.
For cat scratches and bites, I would say that unless they are deep or they develop an infection, the kid should be fine with regular soap and water. I've had cats scratch me as a kid and I just washed the scratches, I never developed an infection and I never had to go to the doctor for any of them.
I would say however that if there are kids, that they should learn how to treat the cat correctly, so the cat doesn't feel compelled to have to bite or scratch. Usually the cat is does after it's other warnings have gone unheeded and the kid is still pushing the cat's boundries. Or sometimes the cat gets excited or upset, which then the best thing would be is to leave the cat alone until it calms down.
I think the thing with pregnant women and litterboxes is mainly the issue with toxoplasmosis, as cats can be a carrier for this parasite. The reason why toxoplasmosis is a danger is that due to a peculiearity of the parasite's lifecyle (it uses it's host's immune system to keep its numbers in check to avoid killing the host) it makes it a danger to unborn babies (they don't have an immune system yet, so the parasite keeps increasing in numbers, thus severely damaging or killing the baby.)
But even with this, pregnant ladies can still empty the litterbox if they take precaution by wearing a filter mask (the kind you see contruction men wear when in dusty areas) and by using rubber gloves and washing their hands afterwards.
As for the cat 'stealing a baby's breath,' that is an old wives tale. Cats don't steal breath, but what they do like to do is lie down in warm places or with people, and a cat will sometimes try to sleep on top of a person and these are what can be a danger for babies.
However, if the cat is kept out of the baby's room then there shouldn't really be an issue, especially if there is a door that can be shut to keep the cat out.
Having a cat does have it's pros and cons (I should know, I have one right now
) but they can be easier to take care of then a dog. A dog requires a bit more work, and plus they have slightly shorter lifespans then a cat. And landlords tend to allow cats more then dogs, as dogs can be messy when left alone for too long and they also have a tendancy to bark. I like dogs, but cats are more 'user friendly.' 
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Crispy Pickles!!