Well Skeletons are able to be prevented in some way, including the config. 
As for the Natural Gas you encountered, it goes upwards so instead of you leaving sideways have you tried just digging 2 blocks down and looking at it from below? Then you should be fine. ^^
Edit: Another way would be digging a little bit upwards in case you’re in a staircase, so the gas goes past you instead of into your face.
Edit2: And always remember, Minecrafts Poison Effect can NOT kill you, it was continuing to have your head inside the Gas that killed you via suffocation.