When you are doing a safety check list, you don't skip and do whatever part of the checklist you feel comfortable doing. 
  You do it from top to bottom. 

  Multiple people have died in accidents because they focused on small issue ignoring the larger problem.

  So when it's time to check safety in scuba diving, you should better follow the instruction instead of doing whatever you want. 
  Example. There is no point to worry about "Is your mask clean?" when you are going to run out of oxygen and drown.