I want to know that I can trust it if I ever need it for home defense
I wouldn't worry overly much about QC from any major manufacturer. It's a pumpgun, not a space capsule (those are built by the lowest bidder too, BTW).
Buy it. Clean it, especially the barrel and chamber, before you ever shoot it.
Then shoot it A LOT. Then clean it again. Rinse and repeat. Don't futz around with the gun, taking it all apart to its smallest pieces etc., just shoot it, field strip it as needed and clean it. I suspect that a certain percentage of people who have trouble with new guns cause that trouble themselves (wonder what this does? Can I make it slam fire?) by doing stuff to/with the gun they have no business doing.
After a while you'll know if you can trust it to function reliably or not. And if you're seriously worried, look for a good used one and buy that.
Happy shopping,
lpl