DIY-ing a parrot cage requires you to really think about the features of a commercial parrot cage and how you will address the needs of the parrot that are taken care of in a commercial cage. How will you do the feeding & water cups, how will you handle the copious amount of poops they make in a day? Comm'l cages have a slide out grill at the bottom, and often a plastic tray under that one to catch the poops. Neither of those shown in the examples above address that.
Re: the mesh you use - either stainless steel (welded or woven) or aluminum are the only 2 safe choices, neither are cheap. DO not use steel zinc plated (galvanized) mesh aka hardware cloth - the zinc is toxic. Using mesh means you have to CAREFULLY address the sharp points where the mesh is cut to size - these are really sharp. If left unaddressed, the parrot will injure itself.
Re: wood framing (or cabinet walls) - if your guy is a real chewer (most parrots are), that frame you spent so much time DIY-ing, well it will be splinters. Depending on the size , a wood frame might last a few years (conures?) to maybe a few months (macaws, large Amazons).
DIY toys - a big thumbs up, they can be made very inexpensively and are supposed to be easy to destroy. DIY cage - seems like its more work then its worth, could be dangerous to your parrot and certainly more effort to keep clean and safe.
