I don't know how old your cats were, how much of a shit you gave about trying to teach them appropriate behavior, how much you perceived was inappropriate behavior vs. shit that pissed you off that was natural cat behavior ... and if you can't clip a cat's claws then you're probably not very cat savvy.
I have one litter pan per cat, the pans are scooped every other day. As for smelling like cats

People that own dogs you can smell "dog smell" in their house so it is what it is. As for scratching your kid, it happens. My kid got the shit scratched out of him when he mistreated a cat when he was little. He came crying to me, I asked him if he was doing something I'd told him not to, he said yes, I said then you rated the scratch, I told you not to do that. I grew up around horses and big dogs and the fact of life is combine kids and animals, you're going to see blood sooner or later -- farmers have known it for centuries. Part of the reason why our children grow up so inconsiderate anymore is because they aren't confronted by the brutal justice/reality check of nature daily.
Look, don't take what I'm saying as judging, because there is no way I'm capable of making a judgement based on the information provided, all I'm saying is its possible part of what pissed you off about your cats was them just being cats, the rest sounds like they might have been young, under-exercised, over exuberant and a little ignorant (as in you didn't give them ground rules, they were too young to learn the rules).
My cats don't climb the window screens, they do jump up on the counters but cats are VERTICAL creatures, it's their nature to seek height anytime. Frankly, I'm not all that hung up on dirt, I wipe a counter before I use it, problem solved. Yes, they knock shit over, which is why I don't have anything in a position they CAN knock over. I like my cats and could give a fuck how my house looks

I've had cats grumble and growl at me when I'm trimming their claws, but not shit on me --
you must have been one pissed off motherfucker when you were handling that cat and it was freaked out, shitting is basically a fear response.
You had a negative experience but if that was the first time you owned cats it's not fair to go around telling everyone cats are assholes, that's all I'm saying.