There are better, more definitive lists out there. The only FOODS 'm aware of that are REALLY dangerous are avocado, caffiene, alcohol and chocolate. Stone fruit pits and appleseeds are also potentially bad enough to be worth listing with the big 4. Also any kind of spoiled food (mold or bacterial contamination). There are also toxic houseplants, some of which are quite common.
The rest of the foodstuffs listed appear on both good and bad lists. If you exclude everything that's on any bad list anywhere you will run out of things to feed.
Aside from those 4 items above, pretty much anything you can/would eat applies to birds as well Note this rule covers stone fruit pits and apple seeds. I'm an adventurous eater, but I wouldn't recommend feeding raw egg, raw meat or raw fish to your bird either. Nothing wrong with them per se, but they are easily contaminated. Here are some things I've seen variously listed as good or bad and what I believe is the truth about them. Even with avocado, it is really the skin and pit that are toxic, the meat COULD be okay, but not really worth the risk. If you want a comprehensive list, try
http://www.avianweb.com/toxicfoods.html. I'm not sure it is perfect but it seems pretty good.
You might want to consider organic fruits and veggies, since birds are also more susceptible to pesticide residues. Lots of sites list which fruits and veggies retain the most residue and you might consider buying at least those organic -- I go for organic grapes and apples, for instance.
Celery -- the fibrous strings might cause crop impactions in some birds, but are very often found on good to feed lists.
Rhubarb -- probably not good raw, as it is really bad for us raw. Cooked should be OK modulo the fiber issue.
Olives -- we don't eat them uncured and cured they are salty. Probably not great nutrition, but I've never seen them listed as harmful either.
Aubergine (Egg Plant) -- this is often listed on good-to-eat lists. The plants leaves ARE toxic, the fruit is apparently not.
Asparagus -- on most good-to-eat lists, very fibrous ones might be a risk for impaction.
Junk food -- high salt and fat and sugar isn't good for birds, but in proportionally tiny portions an occasional nibble isn't really dire.
Dairy products -- tiny portions are OK but birds are essentially lactose intolerant and it won't digest well. Aged cheese and yogurt are the least risky.
Raw potato and sweet potato -- More palatable cooked, but I don't believe actually toxic. Raw sweet potato is fairly commonly recommended
Tomatoes -- listed on some good lists, but are very acidic and raw tomato should probably be limited
Mushrooms -- on many good lists, but can spoil very easily.
Spinach -- on some good lists, some claim too much iron.
Onion, garlic and related plants -- sulfur compounds in raw onions and garlic may cause problems if a lot is consumed often. It metabolizes to compounds that may affect red blood cells. Small amounts cooked are less likely to be a problem. Some people recommend feeding raw garlic, in contradiction to this.
Grapes -- this staple is said by some to cause excessive iron when too many are eaten. Scotty lives on grapes and sprouts, so I hope it isn't so!
Peanuts and Walnuts -- great foods, but in-shell variety are prone to aflatoxin contamination (basically a mold, but you can't see it).
Biggest food danger -- spoiled food, dirty water. Sprouts especially spoil quickly, so while they are GREAT food, be super picky about their freshness and don't leave them in the cage too long.
Then there is the whole lifestyle/cooking thing.
"Teflon" -- this applies to any PTFE-based nonstick coating, not just the brand name. This is going to be most any inexpensive nonstick pan. It is also ubiquitous -- you may find it in your hairdryer, your coffee warmer, your toaster oven, your curling iron. It is VERY VERY toxic when overheated. The good news is that it has to be overheated, but the bad news is that it is far easier to overheat than you might think. If you put a chicken breast in the middle of one of these pans and brown it, the edges of the pan may get much hotter than the chicken, potentially dangerously hot. Of course, you are also ruining your pan if you use it on high heat, so technically this is abusing it, but most people cook this way -- it is safest to get rid of them. Or replace them with the new ($$$) ceramic nonstick pans which work great and are safe. Silicone based nonstick baking pans are OK, too, but you may have to contact the manufacturer to find out what is in the coating.
Self-cleaning ovens -- not only is the smoke generated from the self-clean process potentially harmful, but many of these ovens have a lining that contains PTFEs. When I found out from the manufacturer that my self-cleaning oven DOES contain these compounds I was shocked, because overheated PTFE is not at all good for humans as well as being fatal for birds. I've yet to get a straight answer on how long I would have to have the birds out of the house if I use the cycle, so I haven't used it since we got Scooter. I worry a bit about higher heat roasting as well. I actually wrote the FDA and Consumer Services about this.
Room fresheners, scented candles, perfume, anything you can smell -- there are anecdotes about birds succumbing to scented candles and air fresheners, but it is hard to find any hard information. If you don't care very much, don't use them. If you do care, proceed with caution, and don't use them in the room where your birds are.
Natural gas -- your bird will succumb faster than you will... you should always take a gas leak seriously anyway, but if you smell gas get your bird into fresh air.
Carbon monoxide -- remember the coal mine canaries? Not a bad idea to have a CO detector in your bird room.
Other pets -- some people say cats are toxic to birds. That isn't true, but their mouths and to a lesser extent their claws carry bacteria that are quite dangerous to birds. Any pet bite should be treated by a vet even if it appears minor. That would go for a toddler bite, too -- our mouths are in there somewhere between cat and dog, I think, for nasty bacteria. And of course your cat, dog, snake or ferret or other pet could directly harm your bird -- use caution and supervise any interactions carefully.
Exposure to disease -- if you go to the bird store, or the local park (pigeons carry chlamydia bigtime) wash your hands carefully. In fact, wash them before you handle your birds as a matter of course, and make guests use hand sanitizer or wash.
Toys -- strayed threads, chain that could snag a toe or beak, broken plastic, etc. etc. monitor new toys and inspect old ones regularly.
Oh, and even if you do everything right, your bird can still develop a nutritional deficit, or have an accident. They are darned vulnerable little critters. So try not to become paranoid.