Hesitant to cover butt/crack hair and wondering if there is risk of cancer or anything if I choose to get this area covered?

There is no evidence at all to show that laser hair removal causes cancer.  You should have no hesitation with having it done on any area of the body.

You should have no concern regarding cancer when receiving LHR in any area which is treated. The buttocks is a common area that is treated and should respond well to treatment.