as far as things breaking and whipping back at you and possibly killing you....
a heavy duty blanket placed over chain (the heavier the better) can help reduce amount of swing / whip chain has if it snaps.
if your chain has big enough holes in it. run a rope loosly within the holes through out the chain. and if chain brakes. the rope holes the chain from whipping.
if you have a good size tree nearby, you can add a chain around the other tree and attach a pulley. and use some cable to do things.
regardless of anything you use, chain, cable, rope. it all can and will break and snap and whip back at you at deadly force. been there done that with close calls. i try my best, to drive off straight, and right as the chain, cable, rope gets tight, i try to drive off at a sharp angle. purpose is if it does break and whip. hopefully i will be further off to the side vs directly in the path of the whipping chain, cable, rope.
also do not get a running start and "snap" the chain, cable, rope. high chance what ever you are using will break and whip back at you. just go slow and get things tight.
try to keep your chains, cable, rope. shorter. longer you use, more likely things will break. eerrrrr chain is only good as the weakest link. longer chain is, more likely there is a weaker link. goes for cable and rope as well.