How this product (and any good glucosamine, chondroitin, MSM product) works is to provide the essential building blocks to repair joint tissue. It doesn't work for all joint problems but if your injuries are from training or other types of strain injury, it is very likely to be the best treatment you can take. Try taking it about 1/2 hour before exercise, as this may improve the effectiveness.

Not sure about the joint mobility exercise but exercise is crucial to healthy joints.

Another good product is taking an essential fat product like fish oil.

None of the ingredients are banned in professional sports.

However, there is a tiny chance that the product could contain minute amounts of banned substances.
Unless the product has a logo which says "Drug Screened" or "Doping Free" or words to this effect, you can't be 100% sure that it doesn't contain a tiny amount of banned substance (this is because if products or ingredients are manufactured in the same facility as a "legal" hormone product, or if the raw materials are stored with other ingredients, the product could contain enough for you to fail a test). I know EAS and Maximuscle do have this testing done on their products that claim on the label to be 'drug free'.

However, keep in mind that probably 90% of the Olympians at the Beijing Games used supplements and there were no reports of tainted supplements causing positive doping tests.

There's no need to take a pause from this product, as the ingredients are easily metabolised by the body. However, if your joint pain has subsided and seems to have resolved, then you may want to cycle off it from time to time and/or take it every other day.