I did replace it at the same time. You should be fine driving around on it. I wouldn't go crazy off-road though. Even My old Mopar lift was chewing up my driveshaft.
Yes.. Sounds like she possibly hit something. That light will come on due to the steering wheel being off center.. I would assume for it to be that far off center something had to have been hit fairly decent. . but its only a 3min fix to straighten it back out. As long as nothing got bent.