RE: SERVOS MAKING NOISE
Servos that are hummng are feeling some kind of stress. Most likely a control rod or something is binding. Some servos, especially Hitec's will be jittery when the battery is freshly charges and a minute or two of just moving the sticks will take care of this.
Sevos running on 6 volts are quicker (more responsive) so it's fairly normal to have them feel more sensitive to the sticks
When you have the radio close to the antenna, sometimes this can make a servo or all of them jumpy. To be sure I would look for sources of interference. This also depends sometimes on if you are outside versus inside.
I have the same problem in my shop. I have allot of florencent lights in my ceiling and in some cases having everything turned on and being really close to the plane can cause a jitter. Outside I have no problems