I retooled Profession skills in my current 3.5 game to become more of a catch-all skill that allows you to use them, with varying penalties, if you can justify their use. So, Profession Sailor allows you to make Balance or Climb checks. You would be better at climbing if you had the Climb skill, but, your check will be better than an untrained Climb check.
It works for us.
As far as "is it needed in D&D"? Not really. It comes up far too rarely to be honest. Yes, I know YOUR game uses them all the time, but, I'm going to say fairly confidently that the majority of games barely used the rules, if at all.