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.
set up a profile on any online dating site and you can list your marital status as single, divorced, separated, etc so there is no need to lie about anything, does that settle your worries on hiding information? You control who enters your life and who doesn't, it is YOUR life. Again these are all opinions, my opinion is for the LBS dealing with a WAS who is having an affair, do it, it helps change your mindset, it helps you stop pursuing, it makes you more confident, it helps with a ton of stuff and I think it makes you more attractive to your WAS, you're no longer waiting for them, you no longer become a backup option to them, you remove options from them and add options to you - it's counter-intuitive and it works.