And Again, I call your reasons BS. You have no right to decide what is and is not canon. That's SE's perogative, not yours. Even if new installments are just there to draw in the cash (of course, so was the original. The point is to sell a product, after all), SE putting out new products already includes them into the canon until they say otherwise. This includes any and all retcons.

FANON. This is the term you need to familiarize yourself with. FANON.

And your one example of the "errors" in the game isn't an error. Kadaj was shinentai. It makes sense for him to burst into lifestream as he loses cohesion.