Re: Clicking Ankle
If the ankle thing really were the same thing as cracking your knuckles, it would be fairly harmless. Knuckle cracking has to do with the joint twisting or separating enough to cause sudden, temporary displacement and probably bubbles in the joint's synovial fluid. The ankle could be something like that, or it could be some overly tight muscle's tendon snapping over an obstacle like another tendon or a bone protuberance, or it could be something else I don't know about.
If it's a tendon snapping, it could eventually cause tendonitis or even wear through the tendon - imagine pulling a tense rope sideways over a rock and making it snap thousands of times.
You might be able to correct it by some combination of stretching and changing your posture and movement patterns. It may be possible to lessen the tension in the offending muscle or realign things so that the tendon no longer scrapes. I doubt anyone could find exactly which tendon, so you'd probably be looking at some kind of random assortment of stretches or a discipline where your posture and walking pattern is modified in accordance with some paradigm of what is proper.
The stretches you could try yourself, with a little info - if the plan merely involves stretching, anyone who tells you they aren't mostly guessing or prescribing a 'shotgun' list of them is suspect. For changing the patterns, maybe yoga (that doesn't emphasize stretching), the Alexander Technique, or even something as simple as experimenting with different types of shoes with either more or less support might be worth looking into. I'm guessing you won't want to go into anything expensive or elaborate until you actually experience tendonitis though - if there is no pain, there is no hurry. I personally work to get rid of any such popping as soon as I notice it, just in case - through what I know about yoga and changing my posture and movement habits.
I'd get a sports med doctor and/or physical therapist to look into the hip. It sounds like the whole joint is loose. Restricted movement or 'joint locking' is a pretty serious problem.