yes that is true, youy can warp the rotors. On aluminum wheels if the rims are over tightened it can also cause cracks that spider from the lug holes out in to the rest of the rim. These cracks usually cannot be seen but reduce the load capactiy of the wheel leading to possible faliure. You can use a air gun to remove the lugs but never, never put them back on using one. You have to specify this when you get tires rotated and/or installed, and even then not always going to happen.
Always kick or hit the bottom of the tire. This will elimanate the possiblity of kicking the body of the car or hitting it with a tire. We don't want that now do we?
If swift kicks with the back of you foot don't work rotate the tire 90deg and do it again. This will help to free it up, also.