It sounds like all the OP's complaints are in regards to physical pieces/things that move on the device. After 2 years of use on a device that compact, it's not surprising to see button failures and other physical aspects go haywire.
"The camera pressing thing?" sounds like a button, I think, after two years there's probably a lot of dirt/dust/grime built up inside it. Same with the trackball and the convenience key. And as for the USB, that's all phsyical damage, obvious why it's not working.
The curve is the device I run into the most often, which in my line of work is normally a bad thing as I do troubleshooting, but most, if not, all the time it's because of email issues or browser issues. I really can't recall anyone complaining about anything other than a trackball that hasn't been cleaned properly. I'd have to say you've gotten a good life out of the Curve.
...The bird?... Bird, bird, bird, bird is the word!