OK, I do alignments and stuff for a living, so here's what I think. The only time it's really safe to remove and center a steering wheel is if the rack has ever been replaced, and if the steering column shaft does NOT have a fat spline (probably, like someone said, the column wasn't reattached straight). It's not that it's "unsafe" to center a steering wheel any other time, it just means you're hiding a potential big problem. If your outer tie rods were installed way off (one in too far, the other out too far), that could make your rack hit lock too soon turning one way, and cause you to turn too far going the other way, maybe rubbing a tire in the wheel well. Also, if the outer tie rod is too far out, there may be too few threads holding it on, making it a very weak link. That's probably worst-case, and that doesn't seem that likely, but it still means something could have beeen installed or fixed wrong, or maybe the car was in an accident and the rack shifted in its mounts? In other words, there is an underlying problem to cause the steering wheel to be that crooked, and it should be corrected. Any reputable alignment shop can easily check things out for you, and align it properly. An alignment shop should NEVER remove and center a steering wheel- that is the wrong way to do a proper alignment. (I think there are some old old cars or trucks that have very basic steering adjustments, and I think that is the only time a wheel should be removed and centered as part of proper procedure.)