In response the dead fish at LFS's, if you get to one on a day that shipments are received, it's common to see some major losses. I know of at least one that gets their shipments every Tuesday. Not to say it's a guarantee that's what you experienced, but when you get hundreds of fish in a shipment, you can usually expect some loss.
It's good to see that someone at that Petco is putting some effort into their aquarium section. That one especially since it's about 5 minutes down the road. I personally shop at independent local stores about 95% of the time. My biggest complaint with the super-stores isn't always the conditions, as they're sometimes very good, but allowing shoppers to buy whatever they think looks cool with total disregard for where the fish is going to end up. I know as a retailer, a sale is sometimes a sale, but I've seen some sales that are just downright unacceptable. I'm glad to hear they're taking interest in that as well. If a customer is buying an oscar and a goldfish bowl (which aren't large enough for gold fish either), someone should ask questions...