Today he started to try to open his cage door, has anyone else experienced this?
Some birds love to pick at their cage door locks and try and open the door. Its not a big deal.
If you find he has manages to open the door and you don't want him to do this, you can keep the door closed with a carabiner clip by setting it around the door and cage bars.
You can find these cheap at any hardware store.
He looks great! Healthy and active and busy. Nice pic!
I don't want to scare you but I'd be concerned about the rope perch in his cage. If he chews and consumes the fibers of material this can cause crop blockages and can make the bird really ill.
I have a friend who had a perch like this that had long strands of the material dangling and one of her birds got its foot tangled in the strands, the bird panicked and ended up getting more fibers wrapped around its neck causing it to be strangled.
These rope perches should be replaced as soon as you see its getting ratty. Or you could fix it.
Some people buy Veterinarian Tape and wrap this around the perch to cover the frayed fibers. It's stretchy and goes a long way, you can buy a single roll to last you a long long time. Its not expensive and can be ordered online or found in most vet offices.