It's spine-chilling when a bird gets out without your knowledge, isn't it? I'm glad you're taking steps to try and bird-proof your house. I am too, but it's time-consuming and no one ever gets it completely right. There's always something you didn't count on. For example, my gas-lift chair had been misbehaving and the casters jamming up. I found out why when my corella *picked up a ball-bearing* in her bill and played with it for a few seconds before I managed to get it away from her. My heart stopped!!! When I looked (with my faulty sixty-three-year-old eyes behind their soon-to-be-replaced respectacles), I found there were dozens of ball-bearings in the carpet! Thankfully, Rosetta had only been on the carpet that once, so I know for certain she had only had access to that one ball-bearing. Otherwise, it would've been off to the vet for an x-ray.
Other things I can add to the list:
Ceiling fans can slice, chop or julienne your bird. Make sure you turn them off before letting birdie out of his cage.
Right now in the Australian summer we have a massive insect problem (flies and mosquitoes, but also roaches in dizzying numbers). Be careful of insect sprays and *never* use them in the same room as your bird. Preferably, don't use them at all and stick to traps to reduce insect numbers.
Likewise, other aerols like hairspray, cooking spray, aerosol glues, perfumes etc etc etc. Anything that can mist or outgas fumes is potentially lethal to your bird.
Network cables! Everyone knows electrical cables are dangerous because they carry electricity. However, my Beaks cost us dearly when they attacked the neatly-hidden network cables nestling in the dado of our old house. Poor hubby had to completely dismantle the network and re-wire it. Thanks, Beakies.
Oh, and they killed my sexy classical-music doorbell on the same occasion, chomping through the speaker wire and rendering it incapable of playing Bach at me when the postman rang.
Shoelaces! If you treasure your wonderful trainers, keep them out of birdie's range. He will certainly chew off the aglets (little metal ends of the shoelaces) and leave you with a fuzzy mess. AND the metal in the aglets is probably toxic, so...
Bookcases and tall shelves are a worry because some birds will retreat up there and laugh down at you as you plead with them to come down. We covered some cardboard boxes with tasteful paper and filled the spaces so Beakies couldn't get up there. It's worth filling the spaces above shelved books in the same way to prevent little beaks (peachfaces) from chewing the spines off of your good books. My 'Insects of Australia' has never been the same since the naughty Lovies got a taste for it.
Anything flimsy or unstable the bird could potentially land on - and fall from. I have a collection of Australian Girl dolls (LOL! They look exactly like 'Children of the Damned', all lined up and staring at you) which the birds have occasionally tried to land on. They know better now, but things like standard lamps or those tall CD racks could be really dangerous.
Other pets! We've all seen the cute photos of birds with lions and tigers and bears (oh my!) and cats and dogs. The fact is that it would only take an instant for the bird to either land on or lose its balance and grip hard on the dog or cat, giving it eight simultaneous needles into its skin. Any animal would react instinctively to that and it would only take another tiny instant for the dog or cat to have the bird's head off. I always make sure the dog and cats are entirely out of the room when the birds are out .
Windows and mirrors. Whenever a new bird comes home (not likely to happen again at our place), I always take him around the house, gently touching his bill to the mirrors and windows so he knows they are hard and not to be flown into. I do this every time birdie comes out until I'm convinced he's aware of the danger. The only bird who's ever flown into a window in my house was the little peachface who flew inside from who-knows-where and then tried to fly out again.
This thread could go on and on, but the best idea is to walk through the bird-accessible parts of your house and imagine an inquisitive, flying birdie having free rein there. Then, fix things so he can.
