70-200 on a crop sensor should be about perfect for shooting from the sides.
The 50 f.14 should allow you to cope with really bad light (if you need to) and shallow DoF for isolating small groups of people from the background.
You will need the 18mm for scenes with the whole stage and audience.
It's a similar setup to one I used at a recent festival apart from using the 70-200 with a 1.4TC on full frame (instead of a cropped sensor) and a Fuji X10 for the wide angle.
http://www.wild-landscapes.co.uk/Blog/2012-05-05-Bristol-Folk/22883050_8GWR5H
Your challenge is going to be having just the one camera body as swapping lenses at a concert is not always easy or possible.
I'm lucky enough to have two DSR bodies plus the X10 and a carrying system so I can swap focal lengths instantly by putting one down and picking the next up.
Most of the time I use manual exposure, but in fast changing light levels sometimes aperture priority is better. For close ups, expose for the face (ignore the rest of the image which may be deep black or bleached white but won't really matter). You may find that the lighting on the faces is far more constant than the general lighting as they probably will have spotlighting.
For wide images expose to keep colours in the lighting and effects (ignore the individual performers faces who will usually be exposed badly). With wide scenes metering is very hit and miss!
Keep an eye on the shutter speed, below 1/125s you will be getting quite a lot of motion blur on the performers, which is fine if done deliberately but dramatically reduces the number of keepers if not intentional.
To achieve this, most concert lighting seems to need about ISO 6400 at f5.6. If the D7000 isn't up to this crazy high ISO then stick with your 70-200 f2.8.
Focussing is always a sod as the performers don't like standing still.
For closeups I prefer back button focussing and pre-focus on the face when the performer is standing at the Mic, then wait until they come back to that position. If they do something interesting away from the Mic you have to be quick, but that's where experience and practice come in.
I always take RAW!
Gives me a fighting change to control the lighting colours and tones to give the effect I want, plus maximises the opportunity to recover a great shot that got mis-exposed.
And have fun!