The lens in your camera is a mechanically operated feature. The noises you're hearing are normal movements of the plastic gears inside the lens. These noises are not something to worry about as long as your camera's lens is functioning normally.
The camera is heating up because of the electronic functions of the camera. If you're curious, this is due to the resistance inherent in electrical wiring. Resistance causes the circuits to heat up during use, and is a perfectly normal aspect of operation.
There are three common fixes to a non-working flash. First, make sure your camera is not in Silent Mode. Next, make sure your shutter is set to either auto or MSHTR. If you find that neither of those settings were activated, your solution might be as simple as opening the flash. Open the flash by pressing the P55 button, which is the small, spring activated push-lever located on the left side of the viewfinder.