I'll again preface this as it's my point of view, and it probably differs from yours, which is fine and leads to healthy discussions.
I understand the casual dating/just socializing point of view. I'm good with that if it's someone's cup o'tea. The potential issue is that it puts both "datees" in a vulnerable situation. Rarely does anything serious happen on a first date, I'm with you on that. But, a first date can give EITHER party those warm fuzzies.
Another concern I would have is this. Let's say "Mr Separated" does go on a date. Do you let "Ms Dating Mr Separated" know that you are separated from your spouse? Are women comfortable going on a date (even casual) with a guy she knows is separated from his spouse (or vice versa)? I don't know?
Again, I agree that you don't fall in love with someone on a first date. However, to use a term I've seen on this board, what if you happen to date "Mr or Ms Batchitt Crazy" on a first date and he/she enters your life even on a casual basis.
I respect everyone's opinion and think these discussions are awesome. I happen to like them. But I'll stick with the question that I keep around from my buddy. "Does dating while separated make a possible reconciliation more complicated, or less complicated?"
Some may not be interested in reconciliation. To that I would say you may be more interested in divorce recovery than divorce busting.