Gas lines are potentially dangerous, but people who have worked with them before and know how to handle them should be able to handle installing a gas range safely. However, experts can usually install gas ranges quickly, so the small added cost can be worth spending.
While gas lines are certainly dangerous, gas ranges are also heavy, so it might be best to hire an expert to transport it and move it into place. Without proper moving equipment, heavy ranges can scratch flooring and damage counters and other structures. Dropping the range even a small distance can also damage it, leading to expensive repair bills before it is even installed.