Unlike us, fish do not breathe from the same hole that they eat. Yes, bringing water in through the mouth can help them move it across the gills, but having food in their mouth will not cut off their air supply. It may be uncomfortable, but it shouldnt cause them to suffocate to death.
Rams are notorious for being very difficult to keep alive through the first few weeks. They are sensitive to water conditions and are generally over-bred and in many cases, inbred. Many farm breeders will inject their rams with hormones to make the colors brighter and show sooner to help the fish sell. These all lead to unhealthy fish that look great when you first buy them. I imagine most fish stores carry these types of rams. I would recommend getting them directly from a breeder if you want healthy stock.
I bought my rams from germanbluerams.com. They dont inbreed, over-breed, or inject hormones. I've had my pair for nearly a year. They are fully healthy, have spawned numerous times (though I've never been able to save any fry, they are in a community tank) and have gorgeous coloration that didnt appear until they were the appropriate age. That is what you should look for when buying rams.