Are my refrigerated pork chops & onions safe to eat?

This is not likely a botulism risk. It should be safe to eat assuming the following:

• Refrigerator is functioning properly and keeps food below 40 F.
• Food was not previously sitting out longer than two hours at room temperature.

The USDA provides a useful guide on Refrigeration and Food Safety. This section is pertinent to you:

There are two completely different families of bacteria: pathogenic bacteria, the kind that cause foodborne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes, and textures.

Pathogenic bacteria can grow rapidly in the "Danger Zone," the temperature range between 40 and 140 °F, but they do not generally affect the taste, smell, or appearance of a food. In other words, one cannot tell that a pathogen is present.

Spoilage bacteria can grow at low temperatures, such as in the refrigerator. Eventually they cause food to develop off or bad tastes and smells. Most people would not choose to eat spoiled food, but if they did, they probably would not get sick. It comes down to an issue of quality versus safety:

• Food that has been stored too long in the refrigerator or freezer may be of lessened quality, but most likely would not make anyone sick. (However, some bacteria such as Listeria monocytogenes thrive at cold temperatures, and if present, will multiply in the refrigerator over time and could cause illness.)

According to their storage time chart, cooked pork is approaching spoilage after 3-4 days, i.e. it will start to taste/smell funky. So it should be fine to eat, but of course, use your best judgement — and consider finishing up those chops sooner than later.