Noise from the steering rack could mean a bad ball joint or tie-rod end.Over time it can cause damage or even cause the wheel to fall off.It is a problem but not major and can last 5-6 more year's.Safe bet is to have it checked out.
This could be an indication of a failing power steering pump if it only makes noise on sharp turns. It could also be that the joints need greasing. If it's the power steering, you need to get it checked immediately.
No, you should not be concerned, as that is only a minor problem that can easily be fixed. All you need to do is visit your mechanic and tell him to put some oil on it.