That's 2 out of 700 species? Every animal today is not a bird either...
Dinosaurs with direct observation of feathers.
Archaeopteryx, Sinosauropteryx, Yutyrannus, Ornithomimus, Sinornithosaurus, Microraptor, Caudipteryx, Yi, Epidexipteryx, Sciurumimus
Dinosaurs with quillknobs that very likely held feathers
Velociraptor, Concavenator
Dinosaurs with proto feather like structures or quills
Psittacosaurus, Kulindadromeus
These are just the ones I can name off the top of my head. But this already includes many major dinosaur families. Basal Tetanurans, Allosauria, Comsognathids, Ornithomimids, Dromaeosaurids, Oviraptorosaurs, Tyrannosaurids and even Ceratopsians and other basal ornithischians. We know that at least some included in these families had feathers, protofeathers or quills that were likely analogous to feathers.
Yes that's the assumption. But if the dinosaurs missing the three toes just died out, they are not related to birds. They are related to Euparkeria. Which was not a bird. So again, nothing is facts.
Nature works in mysterious ways. 20 years ago no one would've thought that killer whales were actually wolves and not whales. Nothing in nature is certain, unless we have documented the events. And with dinosaurs we never will.
Stop saying there are no facts in palaeontology, it's simply incorrect.
Do you even know how evolution, and phylogenetics works? Saying dinosaurs that didn't evolve into birds aren't related to birds is just nonsense. If your cousin doesn't have any kids, does that mean they aren't related to your kids? Just because a family of dinosaurs died out does not mean it's not related to some living animal. Yes, ALL dinosaurs are related to birds, some are just more closely related to birds than others. Theropods being the closest and Ornithischians being the least closely related to birds.
Yes, there are a number of things we will never know for sure and we have to make some inferences. But there are a great number of things we actually can know for certain. Saying we can't is a massive disservice to the hundreds of scientists that spend their whole lives studying these amazing extinct animals.
Saying all dinosaurs evolved into birds is also nonsense. A particular lineage of theropod dinosaurs evolved into birds. The rest died out.
All birds are dinosaurs. Not all dinosaurs are birds. This is really not hard.
Saying it's "just a theory" is also very misleading. A theory is an explanation of observed facts. A theory is something that has been tested thoroughly and no problems can be found in it. Theory is the highest possible status something can get in science. It's not just some random idea that someone has that's not based on anything. First you have a wild idea. Then you formulate it so that it becomes a hypothesis, and after you've tested it and it's validated, then it becomes a theory.
Whales are also not wolves. That's nonsense. The closest living relative of the whales that is terrestrial is probably the hippo.