[Broorbbub]

I wouldn't worry about safety hazards too much. Cats are not ferrets, or even dogs; they generally are smart/instinctive/whatever enough to avoid killing themselves. I think this does not hold true for some extremely inbred varieties, but assuming you're not an ass, you'll be adopting them from a shelter anyway, so that shouldn't be a problem. I have three cats, and an apartment that would have about 99.9% chance of killing a crawling baby if I were to have one around, and none of them have died yet, or even suffered any injuries significant enough to be noticed, in the last three or so years