I click huge amounts also... I can click every vertabre from top of neck to base of spine, my knuckles click and also the middle joint on my fingers, toes, ancles, knees (particularly when straightening them), elbows and shoulders in the morning.
I agree it's rarely painful, but is loud.
I've had quite extensive physiotherapy - different people over about 4 years, for a judo accident on one of my vertabre, and all say that there's nothing to be worried about. I've had full body MRI scans and also every scan on my knee that pretty much exists ever, and there is no problem. They just click! I've had blood tests for arthritis and tested for things like fibromyalgia, but there is nothing clinically wrong. No one has ever been concerned or told me there were dangers with the amount of clicking I do.
I also have a good diet, I'm not vegetarian but I eat healthily including lots of calcium, and I'm pretty sporty, have been national in two sports and I don't find that clicking holds me back at all. I actually find clicking loosens whichever joint is concerned, and if often happens unintentionally. However, I do sometimes have joint issues, and feel like I want to click the joint to relieve the pain, so it's not perfect - it seems to me that once one of my joints starts clicking it will continue to do so, and almost 'needs' to for full mobility/rotation.
When I try not to click my neck it feels stiffer and more tender than relieving it by clicking it a few times on each side.